Commit Graph

169 Commits

Author SHA1 Message Date
skylar taylor-barrick 18e2d45420 Merge pull request #6318 from robertoffmoura/fix/floating-selection-move-lag
Fix lag when dragging a floating selection with the Move tool
2026-10-21 14:25:55 -06:00
Roberto Moura 8352b26c1a Fix lag when dragging a floating selection with the Move tool
- Replace whole-region Vec<f32> read_region/write_region in CutParts::new
  with tile-parallel cut_piece + try_fill_surface/try_clear_surface,
  sharing interior Arc<Tile> allocations in O(1) and activating the
  solid_tile hole-fill fast path on Background and mask targets.
- Cache piece_bounds on CutParts so CutParts::place avoids scanning tile
  content bounds on every drag frame.
- Parallelize composite_over across top tiles with Rayon and share fully
  opaque top tiles by Arc<Tile> clone in O(1), preserving COW tile
  identity for GPU canvas uploads.
- Parallelize Surface::translated across target tiles with Rayon and
  prune cleared tiles in-place inside edit_tiles.
- Skip zero-offset floating preview generation on pointer-down in
  move_ui::floating_doc.
- Exclude SnapKind::Selection when moving selected pixels with the Move
  tool so small initial drags do not snap back to (0, 0).
- Keep navigator_plain active during Move/Brush/Patch drags on a GPU
  canvas so navigator_gpu is not evicted into a synchronous full-document
  CPU thumbnail composite on the first drag frame.
- Parallelize row normalization in compose::render_reduced_in_bands and
  add a direct read_rgba_into fast path for unmasked Normal layers over
  an empty backdrop.
2026-10-21 13:21:10 +00:00
aiongg fc371711e6 Merge PR #5847: Shapes: Density and Feather on shape layers (#5846)
# Conflicts:
#	docs/scorecard.md
#	docs/target-app-parity.md
#	docs/ui-parity.md
2026-10-21 05:04:03 +00:00
aiongg 9b889e1a58 Merge PR #6640: Layers: toggling a clipped adjustment damages only its base (#6535) 2026-10-21 01:06:16 +00:00
aiongg 68f8be3967 Merge PR #5791: PSD Multichannel: alpha channels are stored as-is, not as ink (#5790) 2026-10-21 01:06:14 +00:00
aiongg b097800e78 Merge pull request #8095 from aiongg/integration-7
Integration batch: 9 PRs on main
2026-10-20 20:44:51 -04:00
David Mann d089eaa81b Merge PR #7693: perf(compose): Reuse bounded scratch and tone tables 2026-10-20 22:39:29 +02:00
David Mann 651c32b9eb Merge PR #7566: perf(compose, gpu): many-layer composites, P60/P61 on the GPU 111 -> 28 ms 2026-10-20 22:39:26 +02:00
aiongg ea7553f031 Merge PR #5111: Large documents: a gigapixel New Document draws without freezing (#4017) 2026-10-20 18:39:28 +00:00
David Mann 0b39361076 Merge main into feat/tool-214-12-shape-feather 2026-10-20 17:12:29 +02:00
Rene Leonhardt a686a932c0 perf(compose): reuse bounded scratch and tone tables
Reuse tile scratch and tone tables across rendering work. Skip fully masked
adjustments and identity float curves. Previous-path tests preserve output
across sample depths, masks and clipping.
2026-10-20 15:52:44 +02:00
aiongg acc853b517 Merge upstream main into integration-5
docs/file-format-parity.md: keeps both 2026-10-15 rows, main's #6063 PNG sTER row first, then #5976's PSD guides row
2026-10-19 17:20:29 +00:00
David Mann 5c1b9425d1 Gradient Overlay: repaint the whole layer when a stroke moves its frame (#4053) (#5340)
A Gradient Overlay (and gradient strokes, linked patterns, linked bevel
textures) is laid out over the layer's bounds. Painting grows those
bounds, but the stroke commands reported only the stroke as damage, and
the canvas's committed-stroke path repainted only what the live stroke
had not shown. The canvas therefore kept the old gradient around earlier
strokes: one gradient per stroke instead of one over the whole layer.

Session dispatch now grows a command's reported damage by
photocraft_compose::relayout_damage(before, after): the whole composite
of any visible layer whose effects span its frame, when that frame moved.
The canvas adds the same area to a committed live stroke. Strokes inside
the existing bounds and frame-independent effects keep tight damage.

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-10-19 13:04:52 -04:00
David Mann bc4f2a783d Scripts: Flatten All Layer Effects bakes with the document's Global Light and patterns (#5719) (#5720)
`bake` rendered each layer through `render_layer`, which has no document context (default Global
Light, no patterns, the render rect as canvas). It now uses the new doc-aware `render_layer_in`.

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-10-19 13:04:46 -04:00
Akos Arinton dfeba9e974 test(compose): compare NaN as NaN in the vector span test, not by its bits 2026-10-19 18:11:13 +03:00
David Mann c2f3e23a40 Merge PR #5477: perf: chisel bevel size changes, CPU passes on threads and GPU fields share their sharp edges (results unchanged) 2026-10-19 16:51:22 +02:00
David Mann de2cb1f0c0 Compose: a clipped adjustment inside a pass-through clip base damages the whole group (#6535)
A pass-through group that is the base of a clipping group renders isolated while it holds a
visible adjustment (`clip_base_adjusts`), so showing, hiding, adding or removing a clipped
adjustment inside it can switch the group's other children (a Multiply layer beside the base)
between isolated and pass-through rendering. `change_bounds_in` now takes the list holding the
parent group and reports that group's change bounds in this case; `layers_damage`, `step_damage`
and `one_sided_bounds` pass it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-19 14:14:06 +02:00
Akos Arinton 80f896210a perf(compose): write band tiles as they finish, not after the band
Parallel bands each collected their finished tiles until the band's last
one was done, so with work stealing many bands could hold most of their
tiles at once, close to a second copy of the output. Each tile is now put
into its band behind a lock as soon as it is rendered; only the tiles in
flight are held, as before the bands ran in parallel.
2026-10-19 13:34:32 +03:00
David Mann 8534f0c935 Compose: a clipped adjustment with no base inside a pass-through group reaches everything (#6535)
The compositor draws a clipped adjustment that has no unclipped layer
beneath it as an ordinary adjustment, but change_bounds counted it as
contained in a pass-through group. Hiding the layer clipped to such a
group (which ends its isolation) or the group itself then recomposited
only the group's pixels and left the rest of the canvas stale.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-19 10:03:54 +02:00
Akos Arinton 5418399dda perf(compose): blend pixel layers row by row, Normal in 8-pixel vector blocks
A pixel layer with nothing clipped to it is read from its tiles a row at a
time and blended straight onto the backdrop, instead of being copied into a
tile-sized buffer first (a megabyte per layer per 256² render tile). Normal
RGB rows go through a branch-free kernel over blocks of 8 pixels that the
compiler vectorizes; few-band renders also run their bands in parallel.

Bit for bit the same: the row kernel is tested against the scalar loop (NaN,
infinities, subnormals, signed zeros), the row path against the tile copy at
8/16/32-bit with every kind of mode, fill and mask, and the whole GPU parity
suite's CPU references (1620 renders) are unchanged.

P60 on the CPU compositor: 627 -> 530 ms (the render without effects
300 -> 199 ms).
2026-10-18 22:26:05 +03:00
David Mann 0739ff48c5 Merge remote-tracking branch 'origin/main' into fix/4017-huge-new-document
# Conflicts:
#	crates/ui-egui/src/gpu_canvas.rs
#	docs/scorecard.md
#	perf/budgets.toml
2026-10-17 01:07:37 +02:00
David Mann b9d646baad Merge main into fix/multichannel-alpha
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-10-16 22:11:01 +02:00
David Mann 145acbda8b Layers: toggling a clipped adjustment damages only its base (#6535)
`photocraft_compose::change_bounds` returned "anywhere" for every
adjustment layer before looking at `clipped`, although a clipped
adjustment only changes its clip base's pixels. Hiding or showing one
(or undoing that) therefore recomposited the whole canvas, which on a
heavy document fails the GPU memory fit check and falls back to a full
CPU redraw taking seconds to minutes.

`change_bounds` sees one layer and cannot find the base, so a new
`change_bounds_in(layers, k, canvas)` looks at the sibling list: a
clipped adjustment's change bounds are its base's change bounds. It
stays `None` (anywhere) when no unclipped base lies beneath it (the
compositor then draws it as an ordinary adjustment), when the base is
an adjustment (layers clipped to it composite atop the adjusted
backdrop), and, through `change_bounds`, when the base is a
pass-through group holding an adjustment (visible clipped layers make
that group isolated, so they decide whether its adjustment reaches the
layers beneath) or draws outside its bounds. The engine's
`layers_damage`, `step_damage` and `one_sided_bounds` use it.

Tests: a compose unit test that the clipped adjustment's bounds equal
the base's, that every pixel the toggle changes lies inside them, and
the cases that stay unbounded; an engine test that hide, undo, redo,
show and `layer.setProps` visible report the base's rect (top level and
inside a group), and that recompositing only that rect over the
previous canvas equals a full recomposite.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-10-16 15:04:09 +02:00
David Mann ce19e018b9 Merge remote-tracking branch 'origin/main' into feat/tool-214-12-shape-feather
# Conflicts:
#	docs/ui-parity.md
2026-10-15 23:52:29 +02:00
David Mann 24a77a18c0 Shapes: a soft shape's transform frame follows its path (#5846)
A shape below 100 % Density renders over the whole canvas, and a Feather
grows its pixels, so Free Transform, the Move tool's transform controls,
snapping and Properties > Transform framed the canvas or the blur. As in
Photoshop the frame now follows the path and stroke whatever the mask
Density and Feather: photocraft_compose::hard_shape_bounds (shape_bounds
without the soft reach) feeds whole_layer_bounds and the Properties
Transform fields. Rendering keeps the soft bounds; other layers and hard
shapes are unchanged.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-10-15 17:08:05 +02:00
David Mann 442987528f Merge main into fix/4017-huge-new-document
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-10-15 16:52:49 +02:00
skylar taylor-barrick 4e7a17cd5d fix(compose): serialize effect identity cache misses
Keep effect-identity memo lookup, pure hashing and insertion atomic across concurrent render callers. Preserve existing identities and add a contention regression with eight synchronized callers.
2026-10-15 08:18:21 -06:00
David Mann 830676cc7d Merge branch 'main' into fix/multichannel-alpha 2026-10-15 15:54:46 +02:00
David Mann 43d8572c9f Merge remote-tracking branch 'origin/main' into feat/tool-214-12-shape-feather
# Conflicts:
#	docs/scorecard.md
#	docs/ui-parity.md
2026-10-15 12:12:20 +02:00
xsvm 9009683671 refactor(gpu): bevel fields are asked for, windowed and checked as one pair
- the bevel program asks for both fields with B::bevel_fields, so they always come with the
  same reach;
- field and bevel_fields share one windowing (fields_in_windows: one window, or bands on wasm),
  so wasm pairs them per band instead of taking a separate path;
- compose's bevel_height and bevel_distance_fields share bevel_dists;
- sync_fx recomputes the pair together and returns Unsupported when the two are not over the
  same rectangle at the same reach, instead of falling back to one at a time.

Test: paired_bevel_fields_equal_the_fields_one_at_a_time also checks the banded path.
2026-10-15 15:34:03 +08:00
xsvm 5a93e93a44 perf(gpu): a chisel bevel's two fields find their sharp edges once
On the GPU canvas a bevel size change recomputes BevelInside and BevelOutside on the CPU, one
distance_field call each, and each call ran sharp_edges (edge pixels and refined normals) on the
same window again; the CPU compositor already shares them (bevel_height). sharp_edges was ~17% of
the CPU time of those size changes.

When both fields are recomputed over the same rectangle at the same reach (a size change, a new
shape), sync_fx now computes them together: compose::effects::bevel_distance_fields finds the
sharp edges once and returns both. Same window, same functions, so both fields are bit for bit
the ones computed one at a time; the chamfer fields, wasm and a single bevel field keep the old
path.

Test: paired_bevel_fields_equal_the_fields_one_at_a_time (reach 3, 9, 40; whole region and two
parts; bit-equal to field() of each kind).
2026-10-15 15:34:03 +08:00
xsvm d743c2532d perf(compose): bevel maps shade, chisel and mix rows on threads, results unchanged
A chisel bevel size change rebuilds the bevel maps of the whole layer region. The distance
fields already run on threads (#2119), but the passes after them still ran on one thread over
every pixel: the chisel height from the two distances, the texture term, the highlight/shadow
shading (once, or twice for emboss styles) and the emboss inside/outside mix.

Each of these computes a pixel from its own inputs only (the height map, the shape, the
distances), so they now go row by row through par_units / par_fill like the fields: the same
arithmetic in the same order per pixel, so the maps are bit for bit the old ones whatever the
thread count. Maps under 65536 pixels and wasm stay on the calling thread.

Test: bevel_maps_do_not_depend_on_the_threads (4 shapes x 5 styles x 3 techniques, with soften
and a texture, 1 vs 2, 5 and 16 threads, every map bit-equal).
2026-10-15 15:34:02 +08:00
Timothy Daly 4e1e325b17 PSD: a smart object's filter mask shows when the file opens (#5005)
* TIFF: read and write CIE L*a*b* (CIELab, ICCLab); Lab documents stay Lab

Photoshop saves Lab documents as CIELab TIFFs (PhotometricInterpretation
8, a* and b* signed), which PhotoCraft could not open, and PhotoCraft
saved Lab documents as sRGB TIFFs.

- codecs: a Lab channel layout (Lab, LabA) holding a* and b* as
  PhotoCraft's Lab documents do ((a + 128) / 255; 16 bits like the PSD
  importer), with its own Lab <-> sRGB conversion (same formulas as
  photocraft-color; codecs stays standalone) for formats without Lab,
  which now warn LabConverted.
- TIFF read: CIELab and ICCLab (8 and 16 bits, alpha) are handed to the
  tiff crate as RGB and labelled Lab; a* and b* are converted from the
  file's encoding (signed a / 256a, or offset).
- TIFF write: Lab and LabA as CIELab, as Photoshop writes it; float Lab
  is written with 16 bits (DepthReduced).
- io: a Lab TIFF opens as a Lab document; a Lab document with one plain
  layer is written to TIFF in Lab (other formats still use sRGB).

Photoshop 2025's Lab TIFFs open with the colours Photoshop shows (its
own RGB conversion matches within one level at 8 bits and exactly at 16
bits), and Photoshop reads PhotoCraft's Lab TIFFs back with the same
L*a*b* values.

Fixes #4936

* PSD: a smart object's filter mask shows when the file opens

Photoshop stores a smart object's layer pixels with its filters applied
but not its filter mask. When it composites, it mixes the unfiltered
pixels (cached in FEid) back in through the mask. We showed the stored
pixels as they were, so a PSD whose smart filter has a mask opened with
the filter everywhere. Only after something re-rendered the smart object
did the mask appear, because our re-render mixes it.

- compose::filter_mask holds the mix, moved from the engine, and its
  inverse.
- Import decodes the unfiltered pixels from FEid
  (smart_map::unfiltered_from_item) and keeps the mixed result as the
  smart object's pixels, as the engine's re-render does.
- Export writes the layer record the way Photoshop does: unmixed with
  the unfiltered pixels it writes (or keeps) in FEid, so Photoshop mixes
  back to what the document showed. Transparent pixels stay empty.

Photoshop oracles: sf-filter-mask-hard, sf-filter-mask-gradient and
sf-stack-blend-and-mask pass (145 -> 148 of 258); floor 145 -> 148.
psd-tools and io corpora unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* DNG: decode lossy (JPEG-compressed) DNG tiles (FILE-215-11)

DNG 1.4 lossy JPEG (compression 34892) stores each tile or strip as a
baseline-DCT JPEG of 8-bit samples: a gray stream for CFA data, a YCbCr
stream for three-sample LinearRaw. The decoder arm from #2021 read the
streams but widened every sample by 257, so the values no longer matched
the file's levels: an 8-bit WhiteLevel (or its default, 255) clipped
everything to white and a 256-entry LinearizationTable was indexed past
its end. It also required the JPEG frame to match the clipped row count,
which rejected the padded edge tiles real tiled files carry.

The arm is now `lossy_jpeg()` in sensor.rs. The decoded 8-bit values are
the stored samples, and BlackLevel, WhiteLevel (default 255 for 8-bit
data) and the LinearizationTable apply to them exactly as for every other
compression. A tile may be coded at the full tile size (edge tiles padded,
as the spec says) or at the image's row count; a strip at its row count;
the width must be the segment's. BitsPerSample must be 8 and the JPEG's
component count must equal SamplesPerPixel (1 or 3); anything else is an
error, never a silent conversion. The frame header is checked before any
pixel is decoded and the JPEG decoder's own size cap is the segment the
IFD declares (already charged against the limits), so a hostile SOF cannot
size a buffer past the tile.

testgen writes true 8-bit lossy fixtures (`LossyJpegTiles`, and strips via
the new `LossyJpegStrips`), accepts pre-encoded `lossy_segments` for
hostile-input tests, exposes `baseline_jpeg()`, and leaves WhiteLevel out
when `white` is 0. The DNG tests cover CFA and LinearRaw RGB from tiles
and strips at 37x23 (partial edge tiles, a short last strip), the default
white level, black/white scaling and a LinearizationTable against the
uncompressed path, and hostile inputs: a truncated tile, frame-size and
component-count mismatches, a 65535x65535 SOF under default and tight
limits, a tile over the allocation budget, and 12/16-bit or 4-sample
files. The hostile mutation set gains a lossy CFA and a lossy LinearRaw
file. The parity doc's DNG row is updated; the scorecard row is left for
the coordinating branch.

* Raw: measure the Nikon D90 image area (4288x2848 at (10, 10))

Aligning the decoded D90 sensor plane with the camera's own JPEG puts the
image at (10, 10) in the 4352x2868 sensor plane, giving the camera's
4288x2848 frame (10-pixel margins; the right border reads the camera's flat
255 from column 4310). Add the measured ImageArea so a D90 NEF opens on the
camera's frame instead of the uncropped plane, and make a measured profile
leave a file that carries its own colour calibration (a DNG) untouched.

* Codecs: open Cineon (.cin) film frames read-only

Cineon is the 10-bit logarithmic film-scan format DPX grew from. Read it from
the same Kodak header family: the generic header (big-endian, orientation at
192, channel count at 193, the channel-1 bits/dimensions), one or three
channels, three 10-bit samples packed into each 32-bit word on a word
boundary. The 10-bit code values open as U16 (round(c x 65535 / 1023)); the
file's log black/white points are a display choice and are not applied. A
depth other than 10 bits or a channel count other than 1/3 is Unsupported;
truncation errors rather than panicking. Read-only (no Cineon writer), so
.cin joins the open filters and Cineon read closes part of #1049's G10 gap.

* Vector: bound flattening memory, keep over-budget dashes, cheaper edge build (#5195)

- flatten: a path's flattened points are capped at 1 << 20; past it every
  curve keeps a proportional share of its pieces (at least one), so hostile
  handles from files (vmsk, SVG, effect outlines) cannot exhaust memory.
  fill_rasterizer flattens the whole path under one budget.
- stroke: past the dash step budget (or below coordinate precision),
  dash_polyline keeps the dashes made so far and draws the rest solid
  instead of dropping the stroke. Open polylines are no longer copied.
- raster: coordinates are clamped to +-1e15 and edges with a non-finite
  slope (vanishingly short) are skipped, so huge finite coordinates no
  longer produce NaN coverage. fill_rasterizer sorts edges once instead of
  after every component (stable sort, identical order).
- Cleanups: dead miter `half`, dead loop-length check in trace_mask,
  shared mask render body, map_knots helper, shared straight-segment test.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* PSD: cap pattern memory across a parse, reject mixed-depth pattern channels (#5198)

- Patterns: one PatternBudget (decoded bytes + zero padding) is shared by
  every pattern of a block, a .pat file and the pattern blocks of one
  document; .abr patt sections are charged to the samples' budget.
- Patterns: a channel whose depth differs from the first is rejected (the
  parsed pattern could not be written back).
- Slices: descriptor numbers no longer wrap; out-of-range ids are no id,
  coordinates clamp to i32, and a v6 trailing entry without a usable id
  attaches its outsets to no slice.
- LayerInfo::unpadded_len is computed from field sizes instead of
  serializing every record into a scratch buffer.
- abr desc presets are moved out instead of cloned; UnFl and shmd counts
  use the bounded preallocation; ImageData::decode_channel (decoded every
  plane to return one, unused outside its test) is removed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Vector: bound stroke outline points (#5211)

- stroke_polygons dashes all lines first, then counts round caps and
  joins. When their full-resolution tessellation would exceed 1 << 20
  outline points, every round cap and join gets the same smaller segment
  count (down to 4 per circle, 1 per join; area-exact radius kept).
  Strokes under the budget are unchanged; no piece is dropped.
- The dash step budget (100000) is now shared by all lines of a stroke
  instead of per polyline, so many subpaths cannot multiply the dash
  (and cap) count. Past it the rest is drawn solid, as before.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* PSD: write tiff blocks without copies, inflate merged ZIP once

- ImageSourceData::to_bytes writes the global mask and global blocks
  straight from the model with 4-byte alignment instead of cloning each
  block (data included) to set its padding. Same bytes.
- The tiff transcoder's nested regions and blocks write into the parent's
  buffer (taken and handed back, error or not) instead of building their
  own output and copying it up per nesting level. Bodies that fail or are
  not transcoded are truncated before being copied as stored or dropped.
  Same bytes.
- PsdFile::from_bytes_and_merged decodes the merged image with the parse
  when asked: a ZIP stream is inflated once (the decode's stream check is
  the parse's); the parse-only check runs only when the decode fails, to
  keep from_bytes' errors. PSD import uses it with merged_needed.
- PsdBuilder::composite documents that Gray/CMYK composites stay straight.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Content-Aware Fill: measure a thin hole by its thickness, not its bounds (#1366)

Removing long, thin objects (coiled guitar strings, wires) left their
outline as darker and lighter blotches and copied pieces of other strings
into the fill. The pyramid shrank until the hole's bounding box was four
patches across: for a string across the image that is a level where the
hole has swallowed its surroundings, so the matches found there copy
whatever looks like the blur, and the finer levels (refine-only for wide
bounds) keep them.

A hole at most a quarter as thick as its bounds are long now counts as
thin: the pyramid stops while it is still about two patches thick, and
that level starts from a membrane across it (over a few pixels, the
surroundings themselves) instead of the onion peel, whose exhaustive
search is what made a shallow pyramid unaffordable. Compact holes are
unchanged bit for bit.

Refs #1366

* perf(compose,gpu): effect caches reserve tile addresses instead of pinning layers

Effect map cache entries kept a clone of their layer (a deep clone for groups) so the tile addresses the cache key hashes couldn't be reused. That kept an edited or deleted layer's pixels alive, uncounted, until the entry was evicted. Keep a Weak to each hashed tile instead: it reserves the address without keeping the pixels. The GPU compositor's styled-group pins and shape-source tile snapshots do the same. Part of #4530.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(history): count snapshot-only tiles against the history budget

History panel snapshots outlived every budget: a Merged Layers snapshot is a full flattened copy that neither the history budget, the GPU budget's document bytes nor Purge accounted for. Trim now counts the tiles only snapshots hold as fixed cost, the GPU budget includes them, and Purge > Histories no longer reports tiles a kept snapshot still holds as freed. Part of #4530.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Content-Aware Fill: every part of a thin selection keeps its surroundings (#1366)

Two more causes of ghosts when removing strings and the small knobs
selected with them:

* Auto sampling summarises the selection's surroundings by a few
  clusters. Around a long selection those come from the strings'
  surroundings, so a small part elsewhere (a tuning knob in a differently
  coloured corner) lost its own surroundings and was filled from far away
  in another colour. Around a thin selection the Auto area now always
  reaches as far as the selection is thick.
* The membrane that starts a thin hole now starts a patch radius out, past
  the anti-aliased fringe or halo that a selection drawn close to the
  object leaves outside it.

Refs #1366

* Content-Aware Fill: peel a thin hole where that stays affordable (#1366)

Starting every thin hole from a membrane smoothed Spot Healing on film
grain (spot_healing_keeps_film_grain_through_overlapping_strokes: grain
9.0 against 12.1 around). The onion peel copies the grain; it was only
given up because its exhaustive search is too slow on the big level a
long thin hole stops at. It now starts the thin hole whenever hole cells
times sources stay within 2^28 comparisons, and the membrane only beyond.

Refs #1366

* Select Subject: keep subject parts coloured like the backdrop, leave enclosed gaps open

Users on #2788 reported Select Subject dropping clothes that are close in
colour to a plain wall and bridging the gap between an arm and the torso.
Both come from the same place: the saliency pass labels low-contrast parts
of the subject as background, the background colour model then learns
them and explains them away, and the final blind hole fill closes every
enclosed gap up to 5 % of the mask.

Two changes in crates/algo:

- A second GrabCut pass whose background model only knows the backdrop. A
  colour model fitted to the image frame (minus a margin around the
  salient blob, in case the subject runs out of the picture) marks every
  pixel it explains as probable background; the blob and whatever the
  backdrop cannot account for start as probable foreground. Only
  components that touch the first pass's result survive.
- Hole filling that consults the colour models: specks (<= 0.2 % of the
  mask) always fill, larger holes up to 5 % fill only when their pixels
  fit the foreground model better than the background's.

Tests: two regressions (a cream-shouldered figure on a near-white wall
keeps its shoulders; a ring keeps its backdrop-coloured hole open), plus
ignored timing and picture-dump helpers. The 6 MP first run goes from
about 100 ms to about 200 ms on one core; the P29 repeat path is untouched.

* Keyboard shortcut sets: Set menu, New Set, Save, Delete, .kys Export and Summarize (K2)

Edit › Keyboard Shortcuts gets Photoshop's set management. A set is a saved copy of the
bindings (Preferences.shortcutSets, the one in use in shortcutSet; "" is PhotoCraft Defaults),
and the Set menu shows "(modified)" when the bindings differ from it. New Set…, Save and
Delete wait for OK like the rest of the dialog. Export… writes the dialog's bindings as a .kys
file (commands then tools, Photoshop's macOS key spelling), each row carrying our id as pc-id
so PhotoCraft imports its own sets back exactly, whatever the label; Summarize… writes
Photoshop's HTML list of every bound command by menu.

edit.keyboardShortcuts takes useSet (before the call's edits), saveSet, deleteSet, sets and
activeSet (after them), exportKys and summarize; every reply reports the sets, the set in use
and whether it is modified. Bad names, keys or counts are errors that change nothing.

* .kys import: tool keys and sets saved on Windows (K3)

Photoshop's <tool> rows now import: each matches our tool by name (our tool names are
Photoshop's) or by pc-id in sets PhotoCraft exported, and a letter other than the tool's own
becomes its override, while its own letter keeps the tool cycling with the others (#5036).

A set saved on Windows spells the primary modifier Ctrl where a Mac set writes Cmd and keeps
Control for the Control key. A set with no Cmd or Opt anywhere but some Ctrl is read as a
Windows set, its Ctrl as our Cmd: Ctrl+L is the Cmd+L default, not a Control-key override that
would also mean Control on a Mac. The import reports `windows`.

* cargo fmt the extension lists

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Gert Pellin <gert@pellin.be>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Fabio Lissi <fabio.lissi@gmail.com>
Co-authored-by: Vikram Bhaskaran <vikram.bhaskaran@outlook.com>
Co-authored-by: vangel76 <vangel1976@googlemail.com>
Co-authored-by: Finn Newick <finnnk@gmail.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
Co-authored-by: Diego Chagas <drochachagas@gmail.com>
Co-authored-by: Tanish Manku <tmanku.dev@gmail.com>
2026-10-15 00:58:45 -04:00
FinnNk 47cf5af9fd perf: keep effect-cache pins and History snapshots inside the memory budgets (#5336)
* Raw: measure the Nikon D90 image area (4288x2848 at (10, 10))

Aligning the decoded D90 sensor plane with the camera's own JPEG puts the
image at (10, 10) in the 4352x2868 sensor plane, giving the camera's
4288x2848 frame (10-pixel margins; the right border reads the camera's flat
255 from column 4310). Add the measured ImageArea so a D90 NEF opens on the
camera's frame instead of the uncropped plane, and make a measured profile
leave a file that carries its own colour calibration (a DNG) untouched.

* Codecs: open Cineon (.cin) film frames read-only

Cineon is the 10-bit logarithmic film-scan format DPX grew from. Read it from
the same Kodak header family: the generic header (big-endian, orientation at
192, channel count at 193, the channel-1 bits/dimensions), one or three
channels, three 10-bit samples packed into each 32-bit word on a word
boundary. The 10-bit code values open as U16 (round(c x 65535 / 1023)); the
file's log black/white points are a display choice and are not applied. A
depth other than 10 bits or a channel count other than 1/3 is Unsupported;
truncation errors rather than panicking. Read-only (no Cineon writer), so
.cin joins the open filters and Cineon read closes part of #1049's G10 gap.

* PSD: write tiff blocks without copies, inflate merged ZIP once

- ImageSourceData::to_bytes writes the global mask and global blocks
  straight from the model with 4-byte alignment instead of cloning each
  block (data included) to set its padding. Same bytes.
- The tiff transcoder's nested regions and blocks write into the parent's
  buffer (taken and handed back, error or not) instead of building their
  own output and copying it up per nesting level. Bodies that fail or are
  not transcoded are truncated before being copied as stored or dropped.
  Same bytes.
- PsdFile::from_bytes_and_merged decodes the merged image with the parse
  when asked: a ZIP stream is inflated once (the decode's stream check is
  the parse's); the parse-only check runs only when the decode fails, to
  keep from_bytes' errors. PSD import uses it with merged_needed.
- PsdBuilder::composite documents that Gray/CMYK composites stay straight.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Content-Aware Fill: measure a thin hole by its thickness, not its bounds (#1366)

Removing long, thin objects (coiled guitar strings, wires) left their
outline as darker and lighter blotches and copied pieces of other strings
into the fill. The pyramid shrank until the hole's bounding box was four
patches across: for a string across the image that is a level where the
hole has swallowed its surroundings, so the matches found there copy
whatever looks like the blur, and the finer levels (refine-only for wide
bounds) keep them.

A hole at most a quarter as thick as its bounds are long now counts as
thin: the pyramid stops while it is still about two patches thick, and
that level starts from a membrane across it (over a few pixels, the
surroundings themselves) instead of the onion peel, whose exhaustive
search is what made a shallow pyramid unaffordable. Compact holes are
unchanged bit for bit.

Refs #1366

* perf(compose,gpu): effect caches reserve tile addresses instead of pinning layers

Effect map cache entries kept a clone of their layer (a deep clone for groups) so the tile addresses the cache key hashes couldn't be reused. That kept an edited or deleted layer's pixels alive, uncounted, until the entry was evicted. Keep a Weak to each hashed tile instead: it reserves the address without keeping the pixels. The GPU compositor's styled-group pins and shape-source tile snapshots do the same. Part of #4530.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(history): count snapshot-only tiles against the history budget

History panel snapshots outlived every budget: a Merged Layers snapshot is a full flattened copy that neither the history budget, the GPU budget's document bytes nor Purge accounted for. Trim now counts the tiles only snapshots hold as fixed cost, the GPU budget includes them, and Purge > Histories no longer reports tiles a kept snapshot still holds as freed. Part of #4530.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Content-Aware Fill: every part of a thin selection keeps its surroundings (#1366)

Two more causes of ghosts when removing strings and the small knobs
selected with them:

* Auto sampling summarises the selection's surroundings by a few
  clusters. Around a long selection those come from the strings'
  surroundings, so a small part elsewhere (a tuning knob in a differently
  coloured corner) lost its own surroundings and was filled from far away
  in another colour. Around a thin selection the Auto area now always
  reaches as far as the selection is thick.
* The membrane that starts a thin hole now starts a patch radius out, past
  the anti-aliased fringe or halo that a selection drawn close to the
  object leaves outside it.

Refs #1366

* Content-Aware Fill: peel a thin hole where that stays affordable (#1366)

Starting every thin hole from a membrane smoothed Spot Healing on film
grain (spot_healing_keeps_film_grain_through_overlapping_strokes: grain
9.0 against 12.1 around). The onion peel copies the grain; it was only
given up because its exhaustive search is too slow on the big level a
long thin hole stops at. It now starts the thin hole whenever hole cells
times sources stay within 2^28 comparisons, and the membrane only beyond.

Refs #1366

* Select Subject: keep subject parts coloured like the backdrop, leave enclosed gaps open

Users on #2788 reported Select Subject dropping clothes that are close in
colour to a plain wall and bridging the gap between an arm and the torso.
Both come from the same place: the saliency pass labels low-contrast parts
of the subject as background, the background colour model then learns
them and explains them away, and the final blind hole fill closes every
enclosed gap up to 5 % of the mask.

Two changes in crates/algo:

- A second GrabCut pass whose background model only knows the backdrop. A
  colour model fitted to the image frame (minus a margin around the
  salient blob, in case the subject runs out of the picture) marks every
  pixel it explains as probable background; the blob and whatever the
  backdrop cannot account for start as probable foreground. Only
  components that touch the first pass's result survive.
- Hole filling that consults the colour models: specks (<= 0.2 % of the
  mask) always fill, larger holes up to 5 % fill only when their pixels
  fit the foreground model better than the background's.

Tests: two regressions (a cream-shouldered figure on a near-white wall
keeps its shoulders; a ring keeps its backdrop-coloured hole open), plus
ignored timing and picture-dump helpers. The 6 MP first run goes from
about 100 ms to about 200 ms on one core; the P29 repeat path is untouched.

* Keyboard shortcut sets: Set menu, New Set, Save, Delete, .kys Export and Summarize (K2)

Edit › Keyboard Shortcuts gets Photoshop's set management. A set is a saved copy of the
bindings (Preferences.shortcutSets, the one in use in shortcutSet; "" is PhotoCraft Defaults),
and the Set menu shows "(modified)" when the bindings differ from it. New Set…, Save and
Delete wait for OK like the rest of the dialog. Export… writes the dialog's bindings as a .kys
file (commands then tools, Photoshop's macOS key spelling), each row carrying our id as pc-id
so PhotoCraft imports its own sets back exactly, whatever the label; Summarize… writes
Photoshop's HTML list of every bound command by menu.

edit.keyboardShortcuts takes useSet (before the call's edits), saveSet, deleteSet, sets and
activeSet (after them), exportKys and summarize; every reply reports the sets, the set in use
and whether it is modified. Bad names, keys or counts are errors that change nothing.

* .kys import: tool keys and sets saved on Windows (K3)

Photoshop's <tool> rows now import: each matches our tool by name (our tool names are
Photoshop's) or by pc-id in sets PhotoCraft exported, and a letter other than the tool's own
becomes its override, while its own letter keeps the tool cycling with the others (#5036).

A set saved on Windows spells the primary modifier Ctrl where a Mac set writes Cmd and keeps
Control for the Control key. A set with no Cmd or Opt anywhere but some Ctrl is read as a
Windows set, its Ctrl as our Cmd: Ctrl+L is the Cmd+L default, not a Control-key override that
would also mean Control on a Mac. The import reports `windows`.

* cargo fmt the extension lists

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Vikram Bhaskaran <vikram.bhaskaran@outlook.com>
Co-authored-by: vangel76 <vangel1976@googlemail.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Gert Pellin <gert@pellin.be>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
Co-authored-by: Diego Chagas <drochachagas@gmail.com>
Co-authored-by: Tanish Manku <tmanku.dev@gmail.com>
2026-10-15 00:44:55 -04:00
David Mann 6bb45c8d5b Shapes: Density and Feather on shape layers (#5846)
A shape layer's path is its vector mask in Photoshop (Properties > Masks),
with its own vector-mask density and feather. PhotoCraft's ShapeLayer had
neither, so soft shapes could not be made, and stroked soft shapes from PSDs
lost both on import.

- doc: ShapeLayer gains `density` (0..1, default 1) and `feather` (px,
  default 0).
- vector: the shape renderer applies them to the fill as a soft vector mask
  (fill shows beyond the path at 1 - density; the feather is the vector
  mask's Gaussian), so the shape's own pixels, the GPU (which samples them)
  and the stroke/fill split all follow. The stroke stays crisp. The feather
  blur moves from compose::masks to vector::feather and both share it and the
  feathered area, so a shape and an equal vector mask render the same pixels.
- compose: soft shapes' bounds reach their fill, their layer effects follow
  the soft alpha, and the split cache key includes density and feather.
- engine: `layer.vectorMask.edit` on a shape layer sets density/feather in one
  history step (path/enabled/linked/invert are refused there); density is now
  validated (finite 0..100) instead of clamped. `layer.vectorMask.info`
  reports a shape's values.
- ui: Properties shows the Vector Mask Density and Feather sliders for a
  selected shape layer in both themes (live drag, one undo per gesture).
- .pcraft: manifest and convert carry both with serde defaults (older files
  load at 100 % and 0 px).
- PSD: export writes them as the vector density/feather mask parameters;
  import reads them into the shape (re-rendered, as the stored pixels lack the
  fill beyond the path). Soft unstroked solid/gradient shapes now import as
  shapes instead of fill layers with a vector mask; pattern-filled ones stay
  fill layers.

Photoshop's 10 px feather on a 100 px black square, row 100, x = 30..72:
ours is within 1 level of every measured value (8, 16 and 32 bits);
density 50 % shows 127/128 beyond the path and 0 inside.

Scorecard: TOOL-214-12 done.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-10-15 03:07:46 +02:00
David Mann 27c4c56326 Merge main into fix/4017-huge-new-document
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-10-15 00:32:33 +02:00
Michael Higgins 7e94c507e9 Smart Objects: Curves preview no longer zooms in on a reduced proxy (#5766) (#5779)
Adjustments and filters on a smart object add a smart filter, so their live
preview re-renders the smart object from its source through its placement.
The preview runs on a proxy document scaled down by k (large documents), and
proxy_document scaled the smart object's cache but left its transform (and
perspective and filter mask) in full-size document coordinates. The re-render
then came out k times too large on the proxy canvas, so the object looked
zoomed in until OK committed the full-size result.

proxy_document now scales the placement and the filter mask with the proxy.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-14 15:04:19 -07:00
David Mann 667a14d945 PSD Multichannel: alpha channels are stored as-is, not as ink (#5790)
A Multichannel PSD stores ink planes as tone (0 = solid ink), but the
planes DisplayInfo (1077) marks as alpha-type (kind 0/1) are stored as-is,
like alpha channels in every other mode. Import inverted every plane and
export wrote every channel inverted, so a white (selected) alpha imported
as 0 and RGB -> Multichannel -> save wrote alpha channels black.

Measured with a file Photoshop saved itself: a new 8x4 8-bit white RGB
document plus a "selected areas" alpha channel, white left half / black
right half, converted to Multichannel and saved as PSD. Merged planes:
Cyan, Magenta, Yellow = 255 everywhere (ink-inverted: no ink on white
paper); alpha = 255 255 255 255 0 0 0 0 per row (as-is, 255 = selected).
DisplayInfo kinds: 2, 2, 2, 0.

- io: after DisplayInfo, flip alpha-type channels back; on export invert
  only spot channels.
- compose: an alpha-type channel prints as black ink of 1 - value, so the
  composite of a Multichannel file is unchanged.

Tests: a kind-0 alpha imports as stored (white = 1.0) with the spot plane
still read as ink, the composite and the byte-for-byte round trip hold
(8 and 16 bit); a full alpha exports as a max plane next to a solid ink
stored 0. The #4031 composite check now compares against a black ink of
the inverted alpha, within f32 rounding; the compose unit test uses the
as-is polarity for its alpha channel.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-10-14 23:20:06 +02:00
Timothy Daly a62ef68ca2 CMYK: Hue/Saturation and Color Balance keep the black ink (#5000)
* Modern Brightness/Contrast: Photoshop's brightness curve

The modern brightness curve was a line rolled off by a v^P term. It sat
up to 4 levels off Photoshop's in the highlights, and up to 2.3 levels
off for lowered brightness.

The curve is refit to the Photoshop ground truth we have:
- the ±50 samples from 4759d12b;
- the photoshop corpus's brightness +25 / contrast +30 files,
  inverted through the (exact) contrast curve.

Raised, it is the line s*x (s = 1.375^(b/50)) up to a knee at 80/255,
then a cubic Hermite to white with end slope s^-6.6. Lowered, it is the
exact inverse of the curve raised by as much (the -50 samples confirm
this to within a level). Every measured point is within about a level.
For strong values the knee moves down so the curve stays monotone
across -150..150.

Brightness then contrast are evaluated through one 4096-entry table,
built in 55 us. The GPU uses that same table through the Levels/Curves
kernel instead of rebuilding the curves in WGSL, so GPU and CPU agree
by construction.

Photoshop oracles: rgb8/16/32 and gray8/16/32 brightness-contrast now
pass (145 -> 151 of 258). The floor goes 133 -> 151.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK: Brightness/Contrast curves each ink, as Photoshop does

Photoshop applies Brightness/Contrast in a CMYK document to each ink's
stored value, 1 - ink, black included. Both the modern and the legacy
curve do this; the cmyk8 brightness-contrast(-legacy) oracles match it
within a level on every pixel of the files' own inks. Raising
brightness takes ink away. We applied it to the screen colour instead.

- cmyk_channel_adjustment gains Brightness/Contrast. apply_in builds
  the channel curve once (brightness_contrast_lut) and runs each
  separated ink through it (ink_through).
- Destructive Image > Adjustments on a CMYK layer curves the stored
  inks directly, so it is exact; a selection mixes them.
  adjusted_channels now takes the per-pixel operation, and works out
  luma only for CMYK Threshold, which compares it.
- The GPU leaves CMYK Brightness/Contrast to the CPU, like the other
  ink rules.

cmyk8/16 brightness-contrast oracles, bad pixels:
- modern: 72% -> 48-57%, max error 0.19 -> 0.09
- legacy: 71% -> 51-53%

The rest is our separation of the RGB composite, not the rule.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK Threshold compares the inks' own luma, as Photoshop does

Photoshop's CMYK Threshold splits on the Rec. 601 luma of the inks' plain
complement, (1 - c)(1 - k) and so on, whatever the document's profile.
On the files' own inks this puts every pixel of cmyk8 and cmyk16
threshold-128.psd on the right side of level 128. The profile's RGB luma
missed 100.

stored_channels works the luma out from the inks itself (ink_luma), so it
no longer takes one; the engine's stored-channel path no longer converts
each pixel to RGB at all. Through the separated RGB composite the cmyk
threshold oracles drop from 1.6% to 0.2% bad pixels.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK legacy Brightness/Contrast pivots at 128 in ink

Photoshop's legacy contrast pivots at level 128 of the ink, which is 127
of 255 of the stored value (1 - ink) that the curve runs on, not 128 as
in RGB. On Photoshop's own 16-bit inks (cmyk16
brightness-contrast-legacy.psd) ours sat a constant 0.43 of a level
above. That is exactly the one-level pivot shift times contrast +30's
slope minus one; with the pivot moved, the inks match within 0.01.

brightness_contrast_lut is now ink_brightness_contrast_lut, since its
legacy curve is the CMYK one.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK: adjustment layers composite on the document's own inks

The compositor works in display RGB. In a CMYK document, an adjustment
layer that Photoshop evaluates on the inks could only act on our
separation of the RGB composite, and that separation's black differs
from the file's. So even exact ink rules missed: CMYK Invert was 10%
off, Levels and Curves 50-65%.

The ink-native compositor (compose::native, until now only for
flattening plain raster stacks) now takes adjustment layers too:
- Invert, Posterize, Threshold and Brightness/Contrast (modern and
  legacy), and Levels and Curves on CMYK channels, prepared once
  (InkStack, InkOp) and applied to the straight inks.
- Opacity and an unfeathered layer mask mix the inks linearly, as in
  Photoshop; raster layers' masks scale their coverage the same way.
- A CMYK stack of plain raster layers and such adjustments renders this
  way for display, export and reduced views (render_cmyk, tiles in
  parallel); flattening and merging keep the adjusted inks exactly.
- Stacks of raster layers alone keep the RGB compositor, which the GPU
  matches. The GPU already leaves these adjustments to the CPU.

Photoshop oracles: cmyk8 and cmyk16 invert, posterize-4, threshold-128,
levels, curves, brightness-contrast and brightness-contrast-legacy all
pass (14 files), 151 -> 165 of 258; floor 151 -> 165. psd-tools and io
corpora unchanged. 24 MP CMYK8 with one adjustment renders in 286 ms on
the inks, against 442 ms through the RGB compositor.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK ink compositing inlines open groups

The ink compositor gave up on any group. Now a group at full opacity
without a mask is inlined:
- a pass-through group's children composite straight onto the backdrop,
  so an adjustment inside it reaches the layers below;
- an isolated (Normal) group of raster layers alone composites as its
  children would, since Normal is associative.

An isolated group with an adjustment, which only sees the group's
content, keeps the RGB compositor. So do a translucent group and an
artboard. Nesting is bounded.

psd-tools' CMYK adjustment files keep their swatches in pass-through
groups. With #4948's fair comparison, curves_cmyk drops from 37% to 0.3%
bad pixels and levels_cmyk from 14% to 0.2%. The photoshop corpus is
unchanged at 165.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK: Hue/Saturation and Color Balance keep the black ink

In a CMYK document Photoshop applies Hue/Saturation (not Colorize) and
Color Balance to C, M and Y as the complement of an RGB colour, and
leaves the black ink alone. On the photoshop corpus's own inks,
cmyk16 hue-saturation.psd follows this on every pixel within half a
level (cmyk8 within two), and color-balance within our RGB Color
Balance's own error. We applied both to the separated screen colour,
which also rewrote K.

- adjust::cmy_adjustment and apply_cmy run the RGB adjustment once per
  band on (1 - c, 1 - m, 1 - y).
- The ink compositor (InkOp::Cmy), the RGB compositor's CMYK branch and
  destructive Image > Adjustments (pixels::adjusted_cmy) use them. The
  GPU leaves these to the CPU in CMYK documents, as it does the other
  ink rules.
- Colorize separates its colour again, black included, so it keeps the
  screen-colour path.

cmyk8/16 oracles, bad pixels:
- hue-saturation: 100% -> 0.4-0.7%
- color-balance: 74% -> 25%

Neither passes yet. Half a level of cyan ink is three levels of red
through the profile at saturated cyan, and our RGB models leave that
much. The pass count stays at 165.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* 32-bit: legacy Brightness/Contrast, Channel Mixer, Photo Filter and B&W tint unclipped

In 32-bit documents Photoshop keeps these adjustments' results above 1
and below 0. On the photoshop corpus's rgb32/gray32 files:
- Legacy Brightness/Contrast pivots its contrast at 127 of 255 (8/16-bit:
  128) and is exact on every pixel.
- Channel Mixer cuts each source percentage to 1/1024 toward zero, counts
  255/512 of the constant and is exact on pure red, green, blue, black
  and white.
- Photo Filter works on the linear samples, negative results included.
- The Black & White tint is the Color blend mode without the clip at 1,
  as the blend mode is there; white tints to (1.05, 1.00, 0.87).

We clipped all four to 0..1. The GPU kernels follow suit under F_HDR
(the legacy pivot and the mixer's steps come from the planner), and the
HDR parity test covers them.

Photoshop oracles: rgb32 and gray32 brightness-contrast-legacy, rgb32
channel-mixer and black-white-tint pass (145 -> 149 of 258); floor
145 -> 149. rgb32 photo-filter improves (0.19 -> 0.035 max); the rest is
its colour (#3790).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Modern brightness: knee at output 126, fit out to -95 and +150

psd-tools' brightnesscontrast_rgb.psd masks four Brightness/Contrast
layers to their own columns. Read through the exact contrast curve, it
gives Photoshop's brightness at -95, -31, +23 and +150, well past the
+/-50 samples the first fit had. The +/-50 curve extrapolated badly
there: 22 levels off at -95 and 25 at +150.

Every setting puts the knee at about the same output level, not input.
The roll-off's end slope falls as 1/(1 + 0.084 b). With the knee at
126/255 and that end slope, the cubic Hermite fits -95, -50, -31, +23,
+25 and +50 within 1.4 levels. Past about +110 no such cubic stays
below white, so there the roll-off is 1 - (1 - y0)(1 - u)^alpha, with
the slope continuous at the knee. That gives +150 within 6 levels,
where every curve family tried bottoms out. Lowered curves are still
the inverse of raised ones.

The photoshop corpus's six brightness-contrast oracles still pass.
psd-tools brightnesscontrast_rgb goes from 0.13 to 0.020 max error and
_grayscale from 0.098 to 0.016. The new measurements are pinned in
modern_brightness_matches_photoshop.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Levels: whole levels at every step and Photoshop's shadow toe

In 8 bits Photoshop rounds each of the three Levels steps to a whole
level (half up): the input-range stretch (already modelled), the
midtone gamma and the output range. A narrow output range therefore
merges neighbouring gamma levels: psd-tools levels_rgb maps R 43..48 to
58 through a 0.47 channel gamma and the master's 48..255, where the
unrounded curve gave 56..59 (3 levels off in blue).

The gamma above 1 starts along a toe a*u - b*u^q of slope a = 2^gamma
that joins the power curve with the same value and slope (q = 2.2,
fitted). With the rounding, that is exact on 1116 of the 1118 levels
of gamma 1.16, 1.22, 1.3, 1.78 and 2.0 oracles; the soft-min it replaces
missed 52. Gamma below 1 stays the plain power curve (0.67 and 0.7:
every level exact).

Oracles: psd-tools levels_rgb 0.0118 -> 0.0039 (PASS); photoshop
rgb8/stack-levels-curves-hue-posterize 0.2000 -> 0.0000 (PASS); rgb8 and
gray8 levels.psd 0.0039 -> 0.0000; rgb16/gray16 0.0039 -> 0.0020. Floors:
photoshop 145 -> 146, psd-tools 236 -> 238 (main is at 237).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Masks: feathers blur with exactly the feather's variance

A mask feather is a Gaussian with sigma = feather, which we approximate
with three box passes per axis. Whole-pixel boxes rounded the variance:
a 6 px feather blurred like 6.48 px and a 3 px one like 3.46 px, so
feathered edges were too soft by up to 4 levels against Photoshop
(psd-tools mask-parameters-no-real-channel.psd: a 6 px vector and 3 px
pixel feather).

Each pass is now an "extended box" (Gwosdek et al. 2011): weight 1 on
the whole radius and a fractional weight on the two samples beyond it,
so three passes have variance sigma^2 exactly. It stays O(n), reusing
the window's leaving sample for the low end weight (50 MP at a 1000 px
feather: 180 ms parallel, was 172).

psd-tools: mask-parameters-no-real-channel 0.0168 -> 0.0060 (PASS),
layer_mask_data.psd 26.9 % -> 3.9 % of pixels off (psb 25.9 % -> 1.8 %).
Corpus test 239 -> 240; floor 236 -> 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Lab: adjustment layers composite on the stored L, a and b

The compositor reads a Lab document's layers through display RGB, which
clips colours outside its gamut, so the adjustments Photoshop evaluates
on L, a and b (Invert, Posterize, Threshold, Brightness/Contrast, Levels
and Curves with Lab records) only saw the clipped colours: the photoshop
corpus's Lab oracles were up to 11 levels off on saturated colours.

compose::native_lab works a Lab stack of plain layers out on the stored
values instead, like the CMYK ink path: Normal mixes L, a and b
linearly, an opaque layer keeps them exactly, a layer mask scales the
mix, and adjustment layers run adjust::lab_stored_op on each pixel.
Stacks with such adjustments render for display this way; flattening a
plain Lab stack keeps its stored values (exports no longer clip).
Anything else (other blend modes, effects, other adjustments) keeps the
RGB compositor.

Photoshop oracles 145 -> 152: lab16 invert, posterize-4, levels, curves
and brightness-contrast-legacy; lab8 invert and posterize-4. lab8
levels and legacy B/C come within a level (their 8-bit rules are #5143
and #5132). psd-tools and io unchanged; every round trip unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Threshold: split on Photoshop's luminosity of whole samples

Photoshop's Threshold splits on the luminosity 0.30 R + 0.59 G + 0.11 B
(the blend modes' lum, as Gradient Map uses), not the Rec. 601 grey,
taken over the document's whole sample values:

- 8 bits: 30 R + 59 G + 11 B > 100 level - 50, i.e. the luminosity
  rounded to a level with halves down reaches the level;
- 16 bits: 30 R + 59 G + 11 B >= 100 x the level in 16 bits
  (round(level x 32768 / 255): mid grey 16448 is level 128);
- 32 bits: the luminosity reaches the level.

Exact on every pixel of psd-tools threshold_rgb (36432 px; Rec. 601 split
28 the other way), threshold_16bits_rgb (100) and threshold_16bits_
grayscale, and the photoshop corpus's rgb16 threshold-128. The sums are
exact in f32, on the CPU and in the GPU kernel, so ties (grey exactly on
the level) split the same way on both.

psd-tools: threshold_rgb and threshold_16bits_rgb pass; corpus test
239 -> 241, floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Posterize: 16-bit documents bin the 16-bit sample, as Photoshop does

At 16 bits Photoshop doesn't round to 8-bit levels before binning. It
bins the 16-bit sample, floor(v16 * n / 32768), and lands on 8-bit levels
through a 16-bit step: floor(b * 32768 / (n - 1)), converted with
floor((o * 255 + 16384) / 32768). So the middle of 3 levels is 128 where
8 bits give 127, while 42.5 and 25.5 stay 42 and 25.

Exact on every sample of psd-tools posterize_16bits_rgb (levels 3, 7,
13, 21) and posterize_16bits_grayscale (2, 6, 9, 11); the 8-bit rule
missed up to half the range at bin edges. The same rule applies to
CMYK and Lab channels at 16 bits: on the stored inks (#4945's native
path) psd-tools posterize_16bits_cmyk goes from 4.26 % to 0.01 % of
pixels off. 8-bit Posterize is unchanged.

The GPU kernel runs the same rule; 16-bit layers reach it as half
floats, so a sample within their precision of a bin edge can land in
the neighbouring bin there (the CPU, which exports, is exact).

psd-tools 239 -> 241; floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK: Posterize works on the stored values (1 - ink)

Photoshop posterizes a CMYK channel's stored value, 1 - ink, not the
ink: with levels whose steps are uneven (3, 7, 13, 21) the two differ,
e.g. 3 levels take an ink of 85 to 128, where posterizing the ink drops
it to none. psd-tools posterize_cmyk.psd goes from 13.8 % of pixels off
to exact; psd-tools 241 -> 242, floor 242.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Groups: a pass-through clipping base with an adjustment renders isolated

A pass-through group composites its children straight into the
backdrop, so an adjustment layer inside reaches the layers beneath.
When the group is the base of a clipping group and holds an adjustment
layer, Photoshop renders it isolated instead: in psd-tools
passthrough_clipping_mask_adjustment an Exposure in such a group leaves
the layers beneath alone (we darkened them: half the image 170 levels
off). The same group with a Linear Dodge child and no adjustment keeps
reaching the backdrop (passthrough_clipping_mask_blendmode), and so do
clipping-mask3/4/5, so the rule is the adjustment, not the clipping
alone (isolating every pass-through clipping base broke those two).

CPU compositor and GPU plan alike. psd-tools 239 -> 240; floor 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Raise corpus floors to the results of the landed adjustment fixes

Photoshop-authored 165 -> 185 of 258, io 146 -> 148 of 170, psd-tools 242 -> 249 of 309,
measured with the CMYK, Lab, 32-bit, Levels, Threshold, Posterize, feather and
pass-through PRs merged together.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-14 14:12:06 -04:00
Timothy Daly 1e6f565a7b CMYK: adjustment layers composite on the document's own inks (14 oracles pass) (#4945)
* Modern Brightness/Contrast: Photoshop's brightness curve

The modern brightness curve was a line rolled off by a v^P term. It sat
up to 4 levels off Photoshop's in the highlights, and up to 2.3 levels
off for lowered brightness.

The curve is refit to the Photoshop ground truth we have:
- the ±50 samples from 4759d12b;
- the photoshop corpus's brightness +25 / contrast +30 files,
  inverted through the (exact) contrast curve.

Raised, it is the line s*x (s = 1.375^(b/50)) up to a knee at 80/255,
then a cubic Hermite to white with end slope s^-6.6. Lowered, it is the
exact inverse of the curve raised by as much (the -50 samples confirm
this to within a level). Every measured point is within about a level.
For strong values the knee moves down so the curve stays monotone
across -150..150.

Brightness then contrast are evaluated through one 4096-entry table,
built in 55 us. The GPU uses that same table through the Levels/Curves
kernel instead of rebuilding the curves in WGSL, so GPU and CPU agree
by construction.

Photoshop oracles: rgb8/16/32 and gray8/16/32 brightness-contrast now
pass (145 -> 151 of 258). The floor goes 133 -> 151.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK: Brightness/Contrast curves each ink, as Photoshop does

Photoshop applies Brightness/Contrast in a CMYK document to each ink's
stored value, 1 - ink, black included. Both the modern and the legacy
curve do this; the cmyk8 brightness-contrast(-legacy) oracles match it
within a level on every pixel of the files' own inks. Raising
brightness takes ink away. We applied it to the screen colour instead.

- cmyk_channel_adjustment gains Brightness/Contrast. apply_in builds
  the channel curve once (brightness_contrast_lut) and runs each
  separated ink through it (ink_through).
- Destructive Image > Adjustments on a CMYK layer curves the stored
  inks directly, so it is exact; a selection mixes them.
  adjusted_channels now takes the per-pixel operation, and works out
  luma only for CMYK Threshold, which compares it.
- The GPU leaves CMYK Brightness/Contrast to the CPU, like the other
  ink rules.

cmyk8/16 brightness-contrast oracles, bad pixels:
- modern: 72% -> 48-57%, max error 0.19 -> 0.09
- legacy: 71% -> 51-53%

The rest is our separation of the RGB composite, not the rule.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK Threshold compares the inks' own luma, as Photoshop does

Photoshop's CMYK Threshold splits on the Rec. 601 luma of the inks' plain
complement, (1 - c)(1 - k) and so on, whatever the document's profile.
On the files' own inks this puts every pixel of cmyk8 and cmyk16
threshold-128.psd on the right side of level 128. The profile's RGB luma
missed 100.

stored_channels works the luma out from the inks itself (ink_luma), so it
no longer takes one; the engine's stored-channel path no longer converts
each pixel to RGB at all. Through the separated RGB composite the cmyk
threshold oracles drop from 1.6% to 0.2% bad pixels.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK legacy Brightness/Contrast pivots at 128 in ink

Photoshop's legacy contrast pivots at level 128 of the ink, which is 127
of 255 of the stored value (1 - ink) that the curve runs on, not 128 as
in RGB. On Photoshop's own 16-bit inks (cmyk16
brightness-contrast-legacy.psd) ours sat a constant 0.43 of a level
above. That is exactly the one-level pivot shift times contrast +30's
slope minus one; with the pivot moved, the inks match within 0.01.

brightness_contrast_lut is now ink_brightness_contrast_lut, since its
legacy curve is the CMYK one.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK: adjustment layers composite on the document's own inks

The compositor works in display RGB. In a CMYK document, an adjustment
layer that Photoshop evaluates on the inks could only act on our
separation of the RGB composite, and that separation's black differs
from the file's. So even exact ink rules missed: CMYK Invert was 10%
off, Levels and Curves 50-65%.

The ink-native compositor (compose::native, until now only for
flattening plain raster stacks) now takes adjustment layers too:
- Invert, Posterize, Threshold and Brightness/Contrast (modern and
  legacy), and Levels and Curves on CMYK channels, prepared once
  (InkStack, InkOp) and applied to the straight inks.
- Opacity and an unfeathered layer mask mix the inks linearly, as in
  Photoshop; raster layers' masks scale their coverage the same way.
- A CMYK stack of plain raster layers and such adjustments renders this
  way for display, export and reduced views (render_cmyk, tiles in
  parallel); flattening and merging keep the adjusted inks exactly.
- Stacks of raster layers alone keep the RGB compositor, which the GPU
  matches. The GPU already leaves these adjustments to the CPU.

Photoshop oracles: cmyk8 and cmyk16 invert, posterize-4, threshold-128,
levels, curves, brightness-contrast and brightness-contrast-legacy all
pass (14 files), 151 -> 165 of 258; floor 151 -> 165. psd-tools and io
corpora unchanged. 24 MP CMYK8 with one adjustment renders in 286 ms on
the inks, against 442 ms through the RGB compositor.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK ink compositing inlines open groups

The ink compositor gave up on any group. Now a group at full opacity
without a mask is inlined:
- a pass-through group's children composite straight onto the backdrop,
  so an adjustment inside it reaches the layers below;
- an isolated (Normal) group of raster layers alone composites as its
  children would, since Normal is associative.

An isolated group with an adjustment, which only sees the group's
content, keeps the RGB compositor. So do a translucent group and an
artboard. Nesting is bounded.

psd-tools' CMYK adjustment files keep their swatches in pass-through
groups. With #4948's fair comparison, curves_cmyk drops from 37% to 0.3%
bad pixels and levels_cmyk from 14% to 0.2%. The photoshop corpus is
unchanged at 165.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* 32-bit: legacy Brightness/Contrast, Channel Mixer, Photo Filter and B&W tint unclipped

In 32-bit documents Photoshop keeps these adjustments' results above 1
and below 0. On the photoshop corpus's rgb32/gray32 files:
- Legacy Brightness/Contrast pivots its contrast at 127 of 255 (8/16-bit:
  128) and is exact on every pixel.
- Channel Mixer cuts each source percentage to 1/1024 toward zero, counts
  255/512 of the constant and is exact on pure red, green, blue, black
  and white.
- Photo Filter works on the linear samples, negative results included.
- The Black & White tint is the Color blend mode without the clip at 1,
  as the blend mode is there; white tints to (1.05, 1.00, 0.87).

We clipped all four to 0..1. The GPU kernels follow suit under F_HDR
(the legacy pivot and the mixer's steps come from the planner), and the
HDR parity test covers them.

Photoshop oracles: rgb32 and gray32 brightness-contrast-legacy, rgb32
channel-mixer and black-white-tint pass (145 -> 149 of 258); floor
145 -> 149. rgb32 photo-filter improves (0.19 -> 0.035 max); the rest is
its colour (#3790).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Modern brightness: knee at output 126, fit out to -95 and +150

psd-tools' brightnesscontrast_rgb.psd masks four Brightness/Contrast
layers to their own columns. Read through the exact contrast curve, it
gives Photoshop's brightness at -95, -31, +23 and +150, well past the
+/-50 samples the first fit had. The +/-50 curve extrapolated badly
there: 22 levels off at -95 and 25 at +150.

Every setting puts the knee at about the same output level, not input.
The roll-off's end slope falls as 1/(1 + 0.084 b). With the knee at
126/255 and that end slope, the cubic Hermite fits -95, -50, -31, +23,
+25 and +50 within 1.4 levels. Past about +110 no such cubic stays
below white, so there the roll-off is 1 - (1 - y0)(1 - u)^alpha, with
the slope continuous at the knee. That gives +150 within 6 levels,
where every curve family tried bottoms out. Lowered curves are still
the inverse of raised ones.

The photoshop corpus's six brightness-contrast oracles still pass.
psd-tools brightnesscontrast_rgb goes from 0.13 to 0.020 max error and
_grayscale from 0.098 to 0.016. The new measurements are pinned in
modern_brightness_matches_photoshop.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Levels: whole levels at every step and Photoshop's shadow toe

In 8 bits Photoshop rounds each of the three Levels steps to a whole
level (half up): the input-range stretch (already modelled), the
midtone gamma and the output range. A narrow output range therefore
merges neighbouring gamma levels: psd-tools levels_rgb maps R 43..48 to
58 through a 0.47 channel gamma and the master's 48..255, where the
unrounded curve gave 56..59 (3 levels off in blue).

The gamma above 1 starts along a toe a*u - b*u^q of slope a = 2^gamma
that joins the power curve with the same value and slope (q = 2.2,
fitted). With the rounding, that is exact on 1116 of the 1118 levels
of gamma 1.16, 1.22, 1.3, 1.78 and 2.0 oracles; the soft-min it replaces
missed 52. Gamma below 1 stays the plain power curve (0.67 and 0.7:
every level exact).

Oracles: psd-tools levels_rgb 0.0118 -> 0.0039 (PASS); photoshop
rgb8/stack-levels-curves-hue-posterize 0.2000 -> 0.0000 (PASS); rgb8 and
gray8 levels.psd 0.0039 -> 0.0000; rgb16/gray16 0.0039 -> 0.0020. Floors:
photoshop 145 -> 146, psd-tools 236 -> 238 (main is at 237).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Masks: feathers blur with exactly the feather's variance

A mask feather is a Gaussian with sigma = feather, which we approximate
with three box passes per axis. Whole-pixel boxes rounded the variance:
a 6 px feather blurred like 6.48 px and a 3 px one like 3.46 px, so
feathered edges were too soft by up to 4 levels against Photoshop
(psd-tools mask-parameters-no-real-channel.psd: a 6 px vector and 3 px
pixel feather).

Each pass is now an "extended box" (Gwosdek et al. 2011): weight 1 on
the whole radius and a fractional weight on the two samples beyond it,
so three passes have variance sigma^2 exactly. It stays O(n), reusing
the window's leaving sample for the low end weight (50 MP at a 1000 px
feather: 180 ms parallel, was 172).

psd-tools: mask-parameters-no-real-channel 0.0168 -> 0.0060 (PASS),
layer_mask_data.psd 26.9 % -> 3.9 % of pixels off (psb 25.9 % -> 1.8 %).
Corpus test 239 -> 240; floor 236 -> 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Lab: adjustment layers composite on the stored L, a and b

The compositor reads a Lab document's layers through display RGB, which
clips colours outside its gamut, so the adjustments Photoshop evaluates
on L, a and b (Invert, Posterize, Threshold, Brightness/Contrast, Levels
and Curves with Lab records) only saw the clipped colours: the photoshop
corpus's Lab oracles were up to 11 levels off on saturated colours.

compose::native_lab works a Lab stack of plain layers out on the stored
values instead, like the CMYK ink path: Normal mixes L, a and b
linearly, an opaque layer keeps them exactly, a layer mask scales the
mix, and adjustment layers run adjust::lab_stored_op on each pixel.
Stacks with such adjustments render for display this way; flattening a
plain Lab stack keeps its stored values (exports no longer clip).
Anything else (other blend modes, effects, other adjustments) keeps the
RGB compositor.

Photoshop oracles 145 -> 152: lab16 invert, posterize-4, levels, curves
and brightness-contrast-legacy; lab8 invert and posterize-4. lab8
levels and legacy B/C come within a level (their 8-bit rules are #5143
and #5132). psd-tools and io unchanged; every round trip unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Threshold: split on Photoshop's luminosity of whole samples

Photoshop's Threshold splits on the luminosity 0.30 R + 0.59 G + 0.11 B
(the blend modes' lum, as Gradient Map uses), not the Rec. 601 grey,
taken over the document's whole sample values:

- 8 bits: 30 R + 59 G + 11 B > 100 level - 50, i.e. the luminosity
  rounded to a level with halves down reaches the level;
- 16 bits: 30 R + 59 G + 11 B >= 100 x the level in 16 bits
  (round(level x 32768 / 255): mid grey 16448 is level 128);
- 32 bits: the luminosity reaches the level.

Exact on every pixel of psd-tools threshold_rgb (36432 px; Rec. 601 split
28 the other way), threshold_16bits_rgb (100) and threshold_16bits_
grayscale, and the photoshop corpus's rgb16 threshold-128. The sums are
exact in f32, on the CPU and in the GPU kernel, so ties (grey exactly on
the level) split the same way on both.

psd-tools: threshold_rgb and threshold_16bits_rgb pass; corpus test
239 -> 241, floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Posterize: 16-bit documents bin the 16-bit sample, as Photoshop does

At 16 bits Photoshop doesn't round to 8-bit levels before binning. It
bins the 16-bit sample, floor(v16 * n / 32768), and lands on 8-bit levels
through a 16-bit step: floor(b * 32768 / (n - 1)), converted with
floor((o * 255 + 16384) / 32768). So the middle of 3 levels is 128 where
8 bits give 127, while 42.5 and 25.5 stay 42 and 25.

Exact on every sample of psd-tools posterize_16bits_rgb (levels 3, 7,
13, 21) and posterize_16bits_grayscale (2, 6, 9, 11); the 8-bit rule
missed up to half the range at bin edges. The same rule applies to
CMYK and Lab channels at 16 bits: on the stored inks (#4945's native
path) psd-tools posterize_16bits_cmyk goes from 4.26 % to 0.01 % of
pixels off. 8-bit Posterize is unchanged.

The GPU kernel runs the same rule; 16-bit layers reach it as half
floats, so a sample within their precision of a bin edge can land in
the neighbouring bin there (the CPU, which exports, is exact).

psd-tools 239 -> 241; floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK: Posterize works on the stored values (1 - ink)

Photoshop posterizes a CMYK channel's stored value, 1 - ink, not the
ink: with levels whose steps are uneven (3, 7, 13, 21) the two differ,
e.g. 3 levels take an ink of 85 to 128, where posterizing the ink drops
it to none. psd-tools posterize_cmyk.psd goes from 13.8 % of pixels off
to exact; psd-tools 241 -> 242, floor 242.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Groups: a pass-through clipping base with an adjustment renders isolated

A pass-through group composites its children straight into the
backdrop, so an adjustment layer inside reaches the layers beneath.
When the group is the base of a clipping group and holds an adjustment
layer, Photoshop renders it isolated instead: in psd-tools
passthrough_clipping_mask_adjustment an Exposure in such a group leaves
the layers beneath alone (we darkened them: half the image 170 levels
off). The same group with a Linear Dodge child and no adjustment keeps
reaching the backdrop (passthrough_clipping_mask_blendmode), and so do
clipping-mask3/4/5, so the rule is the adjustment, not the clipping
alone (isolating every pass-through clipping base broke those two).

CPU compositor and GPU plan alike. psd-tools 239 -> 240; floor 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-14 14:11:42 -04:00
Timothy Daly 92c7922230 CMYK: Brightness/Contrast curves each ink, as Photoshop does (#4930)
* Modern Brightness/Contrast: Photoshop's brightness curve

The modern brightness curve was a line rolled off by a v^P term. It sat
up to 4 levels off Photoshop's in the highlights, and up to 2.3 levels
off for lowered brightness.

The curve is refit to the Photoshop ground truth we have:
- the ±50 samples from 4759d12b;
- the photoshop corpus's brightness +25 / contrast +30 files,
  inverted through the (exact) contrast curve.

Raised, it is the line s*x (s = 1.375^(b/50)) up to a knee at 80/255,
then a cubic Hermite to white with end slope s^-6.6. Lowered, it is the
exact inverse of the curve raised by as much (the -50 samples confirm
this to within a level). Every measured point is within about a level.
For strong values the knee moves down so the curve stays monotone
across -150..150.

Brightness then contrast are evaluated through one 4096-entry table,
built in 55 us. The GPU uses that same table through the Levels/Curves
kernel instead of rebuilding the curves in WGSL, so GPU and CPU agree
by construction.

Photoshop oracles: rgb8/16/32 and gray8/16/32 brightness-contrast now
pass (145 -> 151 of 258). The floor goes 133 -> 151.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK: Brightness/Contrast curves each ink, as Photoshop does

Photoshop applies Brightness/Contrast in a CMYK document to each ink's
stored value, 1 - ink, black included. Both the modern and the legacy
curve do this; the cmyk8 brightness-contrast(-legacy) oracles match it
within a level on every pixel of the files' own inks. Raising
brightness takes ink away. We applied it to the screen colour instead.

- cmyk_channel_adjustment gains Brightness/Contrast. apply_in builds
  the channel curve once (brightness_contrast_lut) and runs each
  separated ink through it (ink_through).
- Destructive Image > Adjustments on a CMYK layer curves the stored
  inks directly, so it is exact; a selection mixes them.
  adjusted_channels now takes the per-pixel operation, and works out
  luma only for CMYK Threshold, which compares it.
- The GPU leaves CMYK Brightness/Contrast to the CPU, like the other
  ink rules.

cmyk8/16 brightness-contrast oracles, bad pixels:
- modern: 72% -> 48-57%, max error 0.19 -> 0.09
- legacy: 71% -> 51-53%

The rest is our separation of the RGB composite, not the rule.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK Threshold compares the inks' own luma, as Photoshop does

Photoshop's CMYK Threshold splits on the Rec. 601 luma of the inks' plain
complement, (1 - c)(1 - k) and so on, whatever the document's profile.
On the files' own inks this puts every pixel of cmyk8 and cmyk16
threshold-128.psd on the right side of level 128. The profile's RGB luma
missed 100.

stored_channels works the luma out from the inks itself (ink_luma), so it
no longer takes one; the engine's stored-channel path no longer converts
each pixel to RGB at all. Through the separated RGB composite the cmyk
threshold oracles drop from 1.6% to 0.2% bad pixels.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* CMYK legacy Brightness/Contrast pivots at 128 in ink

Photoshop's legacy contrast pivots at level 128 of the ink, which is 127
of 255 of the stored value (1 - ink) that the curve runs on, not 128 as
in RGB. On Photoshop's own 16-bit inks (cmyk16
brightness-contrast-legacy.psd) ours sat a constant 0.43 of a level
above. That is exactly the one-level pivot shift times contrast +30's
slope minus one; with the pivot moved, the inks match within 0.01.

brightness_contrast_lut is now ink_brightness_contrast_lut, since its
legacy curve is the CMYK one.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* 32-bit: legacy Brightness/Contrast, Channel Mixer, Photo Filter and B&W tint unclipped

In 32-bit documents Photoshop keeps these adjustments' results above 1
and below 0. On the photoshop corpus's rgb32/gray32 files:
- Legacy Brightness/Contrast pivots its contrast at 127 of 255 (8/16-bit:
  128) and is exact on every pixel.
- Channel Mixer cuts each source percentage to 1/1024 toward zero, counts
  255/512 of the constant and is exact on pure red, green, blue, black
  and white.
- Photo Filter works on the linear samples, negative results included.
- The Black & White tint is the Color blend mode without the clip at 1,
  as the blend mode is there; white tints to (1.05, 1.00, 0.87).

We clipped all four to 0..1. The GPU kernels follow suit under F_HDR
(the legacy pivot and the mixer's steps come from the planner), and the
HDR parity test covers them.

Photoshop oracles: rgb32 and gray32 brightness-contrast-legacy, rgb32
channel-mixer and black-white-tint pass (145 -> 149 of 258); floor
145 -> 149. rgb32 photo-filter improves (0.19 -> 0.035 max); the rest is
its colour (#3790).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Modern brightness: knee at output 126, fit out to -95 and +150

psd-tools' brightnesscontrast_rgb.psd masks four Brightness/Contrast
layers to their own columns. Read through the exact contrast curve, it
gives Photoshop's brightness at -95, -31, +23 and +150, well past the
+/-50 samples the first fit had. The +/-50 curve extrapolated badly
there: 22 levels off at -95 and 25 at +150.

Every setting puts the knee at about the same output level, not input.
The roll-off's end slope falls as 1/(1 + 0.084 b). With the knee at
126/255 and that end slope, the cubic Hermite fits -95, -50, -31, +23,
+25 and +50 within 1.4 levels. Past about +110 no such cubic stays
below white, so there the roll-off is 1 - (1 - y0)(1 - u)^alpha, with
the slope continuous at the knee. That gives +150 within 6 levels,
where every curve family tried bottoms out. Lowered curves are still
the inverse of raised ones.

The photoshop corpus's six brightness-contrast oracles still pass.
psd-tools brightnesscontrast_rgb goes from 0.13 to 0.020 max error and
_grayscale from 0.098 to 0.016. The new measurements are pinned in
modern_brightness_matches_photoshop.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Levels: whole levels at every step and Photoshop's shadow toe

In 8 bits Photoshop rounds each of the three Levels steps to a whole
level (half up): the input-range stretch (already modelled), the
midtone gamma and the output range. A narrow output range therefore
merges neighbouring gamma levels: psd-tools levels_rgb maps R 43..48 to
58 through a 0.47 channel gamma and the master's 48..255, where the
unrounded curve gave 56..59 (3 levels off in blue).

The gamma above 1 starts along a toe a*u - b*u^q of slope a = 2^gamma
that joins the power curve with the same value and slope (q = 2.2,
fitted). With the rounding, that is exact on 1116 of the 1118 levels
of gamma 1.16, 1.22, 1.3, 1.78 and 2.0 oracles; the soft-min it replaces
missed 52. Gamma below 1 stays the plain power curve (0.67 and 0.7:
every level exact).

Oracles: psd-tools levels_rgb 0.0118 -> 0.0039 (PASS); photoshop
rgb8/stack-levels-curves-hue-posterize 0.2000 -> 0.0000 (PASS); rgb8 and
gray8 levels.psd 0.0039 -> 0.0000; rgb16/gray16 0.0039 -> 0.0020. Floors:
photoshop 145 -> 146, psd-tools 236 -> 238 (main is at 237).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Masks: feathers blur with exactly the feather's variance

A mask feather is a Gaussian with sigma = feather, which we approximate
with three box passes per axis. Whole-pixel boxes rounded the variance:
a 6 px feather blurred like 6.48 px and a 3 px one like 3.46 px, so
feathered edges were too soft by up to 4 levels against Photoshop
(psd-tools mask-parameters-no-real-channel.psd: a 6 px vector and 3 px
pixel feather).

Each pass is now an "extended box" (Gwosdek et al. 2011): weight 1 on
the whole radius and a fractional weight on the two samples beyond it,
so three passes have variance sigma^2 exactly. It stays O(n), reusing
the window's leaving sample for the low end weight (50 MP at a 1000 px
feather: 180 ms parallel, was 172).

psd-tools: mask-parameters-no-real-channel 0.0168 -> 0.0060 (PASS),
layer_mask_data.psd 26.9 % -> 3.9 % of pixels off (psb 25.9 % -> 1.8 %).
Corpus test 239 -> 240; floor 236 -> 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Lab: adjustment layers composite on the stored L, a and b

The compositor reads a Lab document's layers through display RGB, which
clips colours outside its gamut, so the adjustments Photoshop evaluates
on L, a and b (Invert, Posterize, Threshold, Brightness/Contrast, Levels
and Curves with Lab records) only saw the clipped colours: the photoshop
corpus's Lab oracles were up to 11 levels off on saturated colours.

compose::native_lab works a Lab stack of plain layers out on the stored
values instead, like the CMYK ink path: Normal mixes L, a and b
linearly, an opaque layer keeps them exactly, a layer mask scales the
mix, and adjustment layers run adjust::lab_stored_op on each pixel.
Stacks with such adjustments render for display this way; flattening a
plain Lab stack keeps its stored values (exports no longer clip).
Anything else (other blend modes, effects, other adjustments) keeps the
RGB compositor.

Photoshop oracles 145 -> 152: lab16 invert, posterize-4, levels, curves
and brightness-contrast-legacy; lab8 invert and posterize-4. lab8
levels and legacy B/C come within a level (their 8-bit rules are #5143
and #5132). psd-tools and io unchanged; every round trip unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Threshold: split on Photoshop's luminosity of whole samples

Photoshop's Threshold splits on the luminosity 0.30 R + 0.59 G + 0.11 B
(the blend modes' lum, as Gradient Map uses), not the Rec. 601 grey,
taken over the document's whole sample values:

- 8 bits: 30 R + 59 G + 11 B > 100 level - 50, i.e. the luminosity
  rounded to a level with halves down reaches the level;
- 16 bits: 30 R + 59 G + 11 B >= 100 x the level in 16 bits
  (round(level x 32768 / 255): mid grey 16448 is level 128);
- 32 bits: the luminosity reaches the level.

Exact on every pixel of psd-tools threshold_rgb (36432 px; Rec. 601 split
28 the other way), threshold_16bits_rgb (100) and threshold_16bits_
grayscale, and the photoshop corpus's rgb16 threshold-128. The sums are
exact in f32, on the CPU and in the GPU kernel, so ties (grey exactly on
the level) split the same way on both.

psd-tools: threshold_rgb and threshold_16bits_rgb pass; corpus test
239 -> 241, floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Posterize: 16-bit documents bin the 16-bit sample, as Photoshop does

At 16 bits Photoshop doesn't round to 8-bit levels before binning. It
bins the 16-bit sample, floor(v16 * n / 32768), and lands on 8-bit levels
through a 16-bit step: floor(b * 32768 / (n - 1)), converted with
floor((o * 255 + 16384) / 32768). So the middle of 3 levels is 128 where
8 bits give 127, while 42.5 and 25.5 stay 42 and 25.

Exact on every sample of psd-tools posterize_16bits_rgb (levels 3, 7,
13, 21) and posterize_16bits_grayscale (2, 6, 9, 11); the 8-bit rule
missed up to half the range at bin edges. The same rule applies to
CMYK and Lab channels at 16 bits: on the stored inks (#4945's native
path) psd-tools posterize_16bits_cmyk goes from 4.26 % to 0.01 % of
pixels off. 8-bit Posterize is unchanged.

The GPU kernel runs the same rule; 16-bit layers reach it as half
floats, so a sample within their precision of a bin edge can land in
the neighbouring bin there (the CPU, which exports, is exact).

psd-tools 239 -> 241; floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Groups: a pass-through clipping base with an adjustment renders isolated

A pass-through group composites its children straight into the
backdrop, so an adjustment layer inside reaches the layers beneath.
When the group is the base of a clipping group and holds an adjustment
layer, Photoshop renders it isolated instead: in psd-tools
passthrough_clipping_mask_adjustment an Exposure in such a group leaves
the layers beneath alone (we darkened them: half the image 170 levels
off). The same group with a Linear Dodge child and no adjustment keeps
reaching the backdrop (passthrough_clipping_mask_blendmode), and so do
clipping-mask3/4/5, so the rule is the adjustment, not the clipping
alone (isolating every pass-through clipping base broke those two).

CPU compositor and GPU plan alike. psd-tools 239 -> 240; floor 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-14 14:11:19 -04:00
Timothy Daly 00c16f2c6d Modern Brightness/Contrast: Photoshop's brightness curve (six oracles pass) (#4722)
* Modern Brightness/Contrast: Photoshop's brightness curve

The modern brightness curve was a line rolled off by a v^P term. It sat
up to 4 levels off Photoshop's in the highlights, and up to 2.3 levels
off for lowered brightness.

The curve is refit to the Photoshop ground truth we have:
- the ±50 samples from 4759d12b;
- the photoshop corpus's brightness +25 / contrast +30 files,
  inverted through the (exact) contrast curve.

Raised, it is the line s*x (s = 1.375^(b/50)) up to a knee at 80/255,
then a cubic Hermite to white with end slope s^-6.6. Lowered, it is the
exact inverse of the curve raised by as much (the -50 samples confirm
this to within a level). Every measured point is within about a level.
For strong values the knee moves down so the curve stays monotone
across -150..150.

Brightness then contrast are evaluated through one 4096-entry table,
built in 55 us. The GPU uses that same table through the Levels/Curves
kernel instead of rebuilding the curves in WGSL, so GPU and CPU agree
by construction.

Photoshop oracles: rgb8/16/32 and gray8/16/32 brightness-contrast now
pass (145 -> 151 of 258). The floor goes 133 -> 151.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* 32-bit: legacy Brightness/Contrast, Channel Mixer, Photo Filter and B&W tint unclipped

In 32-bit documents Photoshop keeps these adjustments' results above 1
and below 0. On the photoshop corpus's rgb32/gray32 files:
- Legacy Brightness/Contrast pivots its contrast at 127 of 255 (8/16-bit:
  128) and is exact on every pixel.
- Channel Mixer cuts each source percentage to 1/1024 toward zero, counts
  255/512 of the constant and is exact on pure red, green, blue, black
  and white.
- Photo Filter works on the linear samples, negative results included.
- The Black & White tint is the Color blend mode without the clip at 1,
  as the blend mode is there; white tints to (1.05, 1.00, 0.87).

We clipped all four to 0..1. The GPU kernels follow suit under F_HDR
(the legacy pivot and the mixer's steps come from the planner), and the
HDR parity test covers them.

Photoshop oracles: rgb32 and gray32 brightness-contrast-legacy, rgb32
channel-mixer and black-white-tint pass (145 -> 149 of 258); floor
145 -> 149. rgb32 photo-filter improves (0.19 -> 0.035 max); the rest is
its colour (#3790).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Modern brightness: knee at output 126, fit out to -95 and +150

psd-tools' brightnesscontrast_rgb.psd masks four Brightness/Contrast
layers to their own columns. Read through the exact contrast curve, it
gives Photoshop's brightness at -95, -31, +23 and +150, well past the
+/-50 samples the first fit had. The +/-50 curve extrapolated badly
there: 22 levels off at -95 and 25 at +150.

Every setting puts the knee at about the same output level, not input.
The roll-off's end slope falls as 1/(1 + 0.084 b). With the knee at
126/255 and that end slope, the cubic Hermite fits -95, -50, -31, +23,
+25 and +50 within 1.4 levels. Past about +110 no such cubic stays
below white, so there the roll-off is 1 - (1 - y0)(1 - u)^alpha, with
the slope continuous at the knee. That gives +150 within 6 levels,
where every curve family tried bottoms out. Lowered curves are still
the inverse of raised ones.

The photoshop corpus's six brightness-contrast oracles still pass.
psd-tools brightnesscontrast_rgb goes from 0.13 to 0.020 max error and
_grayscale from 0.098 to 0.016. The new measurements are pinned in
modern_brightness_matches_photoshop.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Levels: whole levels at every step and Photoshop's shadow toe

In 8 bits Photoshop rounds each of the three Levels steps to a whole
level (half up): the input-range stretch (already modelled), the
midtone gamma and the output range. A narrow output range therefore
merges neighbouring gamma levels: psd-tools levels_rgb maps R 43..48 to
58 through a 0.47 channel gamma and the master's 48..255, where the
unrounded curve gave 56..59 (3 levels off in blue).

The gamma above 1 starts along a toe a*u - b*u^q of slope a = 2^gamma
that joins the power curve with the same value and slope (q = 2.2,
fitted). With the rounding, that is exact on 1116 of the 1118 levels
of gamma 1.16, 1.22, 1.3, 1.78 and 2.0 oracles; the soft-min it replaces
missed 52. Gamma below 1 stays the plain power curve (0.67 and 0.7:
every level exact).

Oracles: psd-tools levels_rgb 0.0118 -> 0.0039 (PASS); photoshop
rgb8/stack-levels-curves-hue-posterize 0.2000 -> 0.0000 (PASS); rgb8 and
gray8 levels.psd 0.0039 -> 0.0000; rgb16/gray16 0.0039 -> 0.0020. Floors:
photoshop 145 -> 146, psd-tools 236 -> 238 (main is at 237).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Masks: feathers blur with exactly the feather's variance

A mask feather is a Gaussian with sigma = feather, which we approximate
with three box passes per axis. Whole-pixel boxes rounded the variance:
a 6 px feather blurred like 6.48 px and a 3 px one like 3.46 px, so
feathered edges were too soft by up to 4 levels against Photoshop
(psd-tools mask-parameters-no-real-channel.psd: a 6 px vector and 3 px
pixel feather).

Each pass is now an "extended box" (Gwosdek et al. 2011): weight 1 on
the whole radius and a fractional weight on the two samples beyond it,
so three passes have variance sigma^2 exactly. It stays O(n), reusing
the window's leaving sample for the low end weight (50 MP at a 1000 px
feather: 180 ms parallel, was 172).

psd-tools: mask-parameters-no-real-channel 0.0168 -> 0.0060 (PASS),
layer_mask_data.psd 26.9 % -> 3.9 % of pixels off (psb 25.9 % -> 1.8 %).
Corpus test 239 -> 240; floor 236 -> 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Lab: adjustment layers composite on the stored L, a and b

The compositor reads a Lab document's layers through display RGB, which
clips colours outside its gamut, so the adjustments Photoshop evaluates
on L, a and b (Invert, Posterize, Threshold, Brightness/Contrast, Levels
and Curves with Lab records) only saw the clipped colours: the photoshop
corpus's Lab oracles were up to 11 levels off on saturated colours.

compose::native_lab works a Lab stack of plain layers out on the stored
values instead, like the CMYK ink path: Normal mixes L, a and b
linearly, an opaque layer keeps them exactly, a layer mask scales the
mix, and adjustment layers run adjust::lab_stored_op on each pixel.
Stacks with such adjustments render for display this way; flattening a
plain Lab stack keeps its stored values (exports no longer clip).
Anything else (other blend modes, effects, other adjustments) keeps the
RGB compositor.

Photoshop oracles 145 -> 152: lab16 invert, posterize-4, levels, curves
and brightness-contrast-legacy; lab8 invert and posterize-4. lab8
levels and legacy B/C come within a level (their 8-bit rules are #5143
and #5132). psd-tools and io unchanged; every round trip unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Threshold: split on Photoshop's luminosity of whole samples

Photoshop's Threshold splits on the luminosity 0.30 R + 0.59 G + 0.11 B
(the blend modes' lum, as Gradient Map uses), not the Rec. 601 grey,
taken over the document's whole sample values:

- 8 bits: 30 R + 59 G + 11 B > 100 level - 50, i.e. the luminosity
  rounded to a level with halves down reaches the level;
- 16 bits: 30 R + 59 G + 11 B >= 100 x the level in 16 bits
  (round(level x 32768 / 255): mid grey 16448 is level 128);
- 32 bits: the luminosity reaches the level.

Exact on every pixel of psd-tools threshold_rgb (36432 px; Rec. 601 split
28 the other way), threshold_16bits_rgb (100) and threshold_16bits_
grayscale, and the photoshop corpus's rgb16 threshold-128. The sums are
exact in f32, on the CPU and in the GPU kernel, so ties (grey exactly on
the level) split the same way on both.

psd-tools: threshold_rgb and threshold_16bits_rgb pass; corpus test
239 -> 241, floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Posterize: 16-bit documents bin the 16-bit sample, as Photoshop does

At 16 bits Photoshop doesn't round to 8-bit levels before binning. It
bins the 16-bit sample, floor(v16 * n / 32768), and lands on 8-bit levels
through a 16-bit step: floor(b * 32768 / (n - 1)), converted with
floor((o * 255 + 16384) / 32768). So the middle of 3 levels is 128 where
8 bits give 127, while 42.5 and 25.5 stay 42 and 25.

Exact on every sample of psd-tools posterize_16bits_rgb (levels 3, 7,
13, 21) and posterize_16bits_grayscale (2, 6, 9, 11); the 8-bit rule
missed up to half the range at bin edges. The same rule applies to
CMYK and Lab channels at 16 bits: on the stored inks (#4945's native
path) psd-tools posterize_16bits_cmyk goes from 4.26 % to 0.01 % of
pixels off. 8-bit Posterize is unchanged.

The GPU kernel runs the same rule; 16-bit layers reach it as half
floats, so a sample within their precision of a bin edge can land in
the neighbouring bin there (the CPU, which exports, is exact).

psd-tools 239 -> 241; floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Groups: a pass-through clipping base with an adjustment renders isolated

A pass-through group composites its children straight into the
backdrop, so an adjustment layer inside reaches the layers beneath.
When the group is the base of a clipping group and holds an adjustment
layer, Photoshop renders it isolated instead: in psd-tools
passthrough_clipping_mask_adjustment an Exposure in such a group leaves
the layers beneath alone (we darkened them: half the image 170 levels
off). The same group with a Linear Dodge child and no adjustment keeps
reaching the backdrop (passthrough_clipping_mask_blendmode), and so do
clipping-mask3/4/5, so the rule is the adjustment, not the clipping
alone (isolating every pass-through clipping base broke those two).

CPU compositor and GPU plan alike. psd-tools 239 -> 240; floor 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-14 14:10:57 -04:00
Timothy Daly 4c450b3879 Lab: adjustment layers composite on the stored L, a and b (seven Lab oracles pass) (#5171)
* 32-bit: legacy Brightness/Contrast, Channel Mixer, Photo Filter and B&W tint unclipped

In 32-bit documents Photoshop keeps these adjustments' results above 1
and below 0. On the photoshop corpus's rgb32/gray32 files:
- Legacy Brightness/Contrast pivots its contrast at 127 of 255 (8/16-bit:
  128) and is exact on every pixel.
- Channel Mixer cuts each source percentage to 1/1024 toward zero, counts
  255/512 of the constant and is exact on pure red, green, blue, black
  and white.
- Photo Filter works on the linear samples, negative results included.
- The Black & White tint is the Color blend mode without the clip at 1,
  as the blend mode is there; white tints to (1.05, 1.00, 0.87).

We clipped all four to 0..1. The GPU kernels follow suit under F_HDR
(the legacy pivot and the mixer's steps come from the planner), and the
HDR parity test covers them.

Photoshop oracles: rgb32 and gray32 brightness-contrast-legacy, rgb32
channel-mixer and black-white-tint pass (145 -> 149 of 258); floor
145 -> 149. rgb32 photo-filter improves (0.19 -> 0.035 max); the rest is
its colour (#3790).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Levels: whole levels at every step and Photoshop's shadow toe

In 8 bits Photoshop rounds each of the three Levels steps to a whole
level (half up): the input-range stretch (already modelled), the
midtone gamma and the output range. A narrow output range therefore
merges neighbouring gamma levels: psd-tools levels_rgb maps R 43..48 to
58 through a 0.47 channel gamma and the master's 48..255, where the
unrounded curve gave 56..59 (3 levels off in blue).

The gamma above 1 starts along a toe a*u - b*u^q of slope a = 2^gamma
that joins the power curve with the same value and slope (q = 2.2,
fitted). With the rounding, that is exact on 1116 of the 1118 levels
of gamma 1.16, 1.22, 1.3, 1.78 and 2.0 oracles; the soft-min it replaces
missed 52. Gamma below 1 stays the plain power curve (0.67 and 0.7:
every level exact).

Oracles: psd-tools levels_rgb 0.0118 -> 0.0039 (PASS); photoshop
rgb8/stack-levels-curves-hue-posterize 0.2000 -> 0.0000 (PASS); rgb8 and
gray8 levels.psd 0.0039 -> 0.0000; rgb16/gray16 0.0039 -> 0.0020. Floors:
photoshop 145 -> 146, psd-tools 236 -> 238 (main is at 237).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Masks: feathers blur with exactly the feather's variance

A mask feather is a Gaussian with sigma = feather, which we approximate
with three box passes per axis. Whole-pixel boxes rounded the variance:
a 6 px feather blurred like 6.48 px and a 3 px one like 3.46 px, so
feathered edges were too soft by up to 4 levels against Photoshop
(psd-tools mask-parameters-no-real-channel.psd: a 6 px vector and 3 px
pixel feather).

Each pass is now an "extended box" (Gwosdek et al. 2011): weight 1 on
the whole radius and a fractional weight on the two samples beyond it,
so three passes have variance sigma^2 exactly. It stays O(n), reusing
the window's leaving sample for the low end weight (50 MP at a 1000 px
feather: 180 ms parallel, was 172).

psd-tools: mask-parameters-no-real-channel 0.0168 -> 0.0060 (PASS),
layer_mask_data.psd 26.9 % -> 3.9 % of pixels off (psb 25.9 % -> 1.8 %).
Corpus test 239 -> 240; floor 236 -> 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Lab: adjustment layers composite on the stored L, a and b

The compositor reads a Lab document's layers through display RGB, which
clips colours outside its gamut, so the adjustments Photoshop evaluates
on L, a and b (Invert, Posterize, Threshold, Brightness/Contrast, Levels
and Curves with Lab records) only saw the clipped colours: the photoshop
corpus's Lab oracles were up to 11 levels off on saturated colours.

compose::native_lab works a Lab stack of plain layers out on the stored
values instead, like the CMYK ink path: Normal mixes L, a and b
linearly, an opaque layer keeps them exactly, a layer mask scales the
mix, and adjustment layers run adjust::lab_stored_op on each pixel.
Stacks with such adjustments render for display this way; flattening a
plain Lab stack keeps its stored values (exports no longer clip).
Anything else (other blend modes, effects, other adjustments) keeps the
RGB compositor.

Photoshop oracles 145 -> 152: lab16 invert, posterize-4, levels, curves
and brightness-contrast-legacy; lab8 invert and posterize-4. lab8
levels and legacy B/C come within a level (their 8-bit rules are #5143
and #5132). psd-tools and io unchanged; every round trip unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Threshold: split on Photoshop's luminosity of whole samples

Photoshop's Threshold splits on the luminosity 0.30 R + 0.59 G + 0.11 B
(the blend modes' lum, as Gradient Map uses), not the Rec. 601 grey,
taken over the document's whole sample values:

- 8 bits: 30 R + 59 G + 11 B > 100 level - 50, i.e. the luminosity
  rounded to a level with halves down reaches the level;
- 16 bits: 30 R + 59 G + 11 B >= 100 x the level in 16 bits
  (round(level x 32768 / 255): mid grey 16448 is level 128);
- 32 bits: the luminosity reaches the level.

Exact on every pixel of psd-tools threshold_rgb (36432 px; Rec. 601 split
28 the other way), threshold_16bits_rgb (100) and threshold_16bits_
grayscale, and the photoshop corpus's rgb16 threshold-128. The sums are
exact in f32, on the CPU and in the GPU kernel, so ties (grey exactly on
the level) split the same way on both.

psd-tools: threshold_rgb and threshold_16bits_rgb pass; corpus test
239 -> 241, floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Posterize: 16-bit documents bin the 16-bit sample, as Photoshop does

At 16 bits Photoshop doesn't round to 8-bit levels before binning. It
bins the 16-bit sample, floor(v16 * n / 32768), and lands on 8-bit levels
through a 16-bit step: floor(b * 32768 / (n - 1)), converted with
floor((o * 255 + 16384) / 32768). So the middle of 3 levels is 128 where
8 bits give 127, while 42.5 and 25.5 stay 42 and 25.

Exact on every sample of psd-tools posterize_16bits_rgb (levels 3, 7,
13, 21) and posterize_16bits_grayscale (2, 6, 9, 11); the 8-bit rule
missed up to half the range at bin edges. The same rule applies to
CMYK and Lab channels at 16 bits: on the stored inks (#4945's native
path) psd-tools posterize_16bits_cmyk goes from 4.26 % to 0.01 % of
pixels off. 8-bit Posterize is unchanged.

The GPU kernel runs the same rule; 16-bit layers reach it as half
floats, so a sample within their precision of a bin edge can land in
the neighbouring bin there (the CPU, which exports, is exact).

psd-tools 239 -> 241; floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Groups: a pass-through clipping base with an adjustment renders isolated

A pass-through group composites its children straight into the
backdrop, so an adjustment layer inside reaches the layers beneath.
When the group is the base of a clipping group and holds an adjustment
layer, Photoshop renders it isolated instead: in psd-tools
passthrough_clipping_mask_adjustment an Exposure in such a group leaves
the layers beneath alone (we darkened them: half the image 170 levels
off). The same group with a Linear Dodge child and no adjustment keeps
reaching the backdrop (passthrough_clipping_mask_blendmode), and so do
clipping-mask3/4/5, so the rule is the adjustment, not the clipping
alone (isolating every pass-through clipping base broke those two).

CPU compositor and GPU plan alike. psd-tools 239 -> 240; floor 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-14 14:10:36 -04:00
Timothy Daly d24f6e9d5f Levels: whole levels at every step and Photoshop's shadow toe (levels_rgb + stack oracle pass) (#5143)
* 32-bit: legacy Brightness/Contrast, Channel Mixer, Photo Filter and B&W tint unclipped

In 32-bit documents Photoshop keeps these adjustments' results above 1
and below 0. On the photoshop corpus's rgb32/gray32 files:
- Legacy Brightness/Contrast pivots its contrast at 127 of 255 (8/16-bit:
  128) and is exact on every pixel.
- Channel Mixer cuts each source percentage to 1/1024 toward zero, counts
  255/512 of the constant and is exact on pure red, green, blue, black
  and white.
- Photo Filter works on the linear samples, negative results included.
- The Black & White tint is the Color blend mode without the clip at 1,
  as the blend mode is there; white tints to (1.05, 1.00, 0.87).

We clipped all four to 0..1. The GPU kernels follow suit under F_HDR
(the legacy pivot and the mixer's steps come from the planner), and the
HDR parity test covers them.

Photoshop oracles: rgb32 and gray32 brightness-contrast-legacy, rgb32
channel-mixer and black-white-tint pass (145 -> 149 of 258); floor
145 -> 149. rgb32 photo-filter improves (0.19 -> 0.035 max); the rest is
its colour (#3790).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Levels: whole levels at every step and Photoshop's shadow toe

In 8 bits Photoshop rounds each of the three Levels steps to a whole
level (half up): the input-range stretch (already modelled), the
midtone gamma and the output range. A narrow output range therefore
merges neighbouring gamma levels: psd-tools levels_rgb maps R 43..48 to
58 through a 0.47 channel gamma and the master's 48..255, where the
unrounded curve gave 56..59 (3 levels off in blue).

The gamma above 1 starts along a toe a*u - b*u^q of slope a = 2^gamma
that joins the power curve with the same value and slope (q = 2.2,
fitted). With the rounding, that is exact on 1116 of the 1118 levels
of gamma 1.16, 1.22, 1.3, 1.78 and 2.0 oracles; the soft-min it replaces
missed 52. Gamma below 1 stays the plain power curve (0.67 and 0.7:
every level exact).

Oracles: psd-tools levels_rgb 0.0118 -> 0.0039 (PASS); photoshop
rgb8/stack-levels-curves-hue-posterize 0.2000 -> 0.0000 (PASS); rgb8 and
gray8 levels.psd 0.0039 -> 0.0000; rgb16/gray16 0.0039 -> 0.0020. Floors:
photoshop 145 -> 146, psd-tools 236 -> 238 (main is at 237).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Masks: feathers blur with exactly the feather's variance

A mask feather is a Gaussian with sigma = feather, which we approximate
with three box passes per axis. Whole-pixel boxes rounded the variance:
a 6 px feather blurred like 6.48 px and a 3 px one like 3.46 px, so
feathered edges were too soft by up to 4 levels against Photoshop
(psd-tools mask-parameters-no-real-channel.psd: a 6 px vector and 3 px
pixel feather).

Each pass is now an "extended box" (Gwosdek et al. 2011): weight 1 on
the whole radius and a fractional weight on the two samples beyond it,
so three passes have variance sigma^2 exactly. It stays O(n), reusing
the window's leaving sample for the low end weight (50 MP at a 1000 px
feather: 180 ms parallel, was 172).

psd-tools: mask-parameters-no-real-channel 0.0168 -> 0.0060 (PASS),
layer_mask_data.psd 26.9 % -> 3.9 % of pixels off (psb 25.9 % -> 1.8 %).
Corpus test 239 -> 240; floor 236 -> 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Threshold: split on Photoshop's luminosity of whole samples

Photoshop's Threshold splits on the luminosity 0.30 R + 0.59 G + 0.11 B
(the blend modes' lum, as Gradient Map uses), not the Rec. 601 grey,
taken over the document's whole sample values:

- 8 bits: 30 R + 59 G + 11 B > 100 level - 50, i.e. the luminosity
  rounded to a level with halves down reaches the level;
- 16 bits: 30 R + 59 G + 11 B >= 100 x the level in 16 bits
  (round(level x 32768 / 255): mid grey 16448 is level 128);
- 32 bits: the luminosity reaches the level.

Exact on every pixel of psd-tools threshold_rgb (36432 px; Rec. 601 split
28 the other way), threshold_16bits_rgb (100) and threshold_16bits_
grayscale, and the photoshop corpus's rgb16 threshold-128. The sums are
exact in f32, on the CPU and in the GPU kernel, so ties (grey exactly on
the level) split the same way on both.

psd-tools: threshold_rgb and threshold_16bits_rgb pass; corpus test
239 -> 241, floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Posterize: 16-bit documents bin the 16-bit sample, as Photoshop does

At 16 bits Photoshop doesn't round to 8-bit levels before binning. It
bins the 16-bit sample, floor(v16 * n / 32768), and lands on 8-bit levels
through a 16-bit step: floor(b * 32768 / (n - 1)), converted with
floor((o * 255 + 16384) / 32768). So the middle of 3 levels is 128 where
8 bits give 127, while 42.5 and 25.5 stay 42 and 25.

Exact on every sample of psd-tools posterize_16bits_rgb (levels 3, 7,
13, 21) and posterize_16bits_grayscale (2, 6, 9, 11); the 8-bit rule
missed up to half the range at bin edges. The same rule applies to
CMYK and Lab channels at 16 bits: on the stored inks (#4945's native
path) psd-tools posterize_16bits_cmyk goes from 4.26 % to 0.01 % of
pixels off. 8-bit Posterize is unchanged.

The GPU kernel runs the same rule; 16-bit layers reach it as half
floats, so a sample within their precision of a bin edge can land in
the neighbouring bin there (the CPU, which exports, is exact).

psd-tools 239 -> 241; floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Groups: a pass-through clipping base with an adjustment renders isolated

A pass-through group composites its children straight into the
backdrop, so an adjustment layer inside reaches the layers beneath.
When the group is the base of a clipping group and holds an adjustment
layer, Photoshop renders it isolated instead: in psd-tools
passthrough_clipping_mask_adjustment an Exposure in such a group leaves
the layers beneath alone (we darkened them: half the image 170 levels
off). The same group with a Linear Dodge child and no adjustment keeps
reaching the backdrop (passthrough_clipping_mask_blendmode), and so do
clipping-mask3/4/5, so the rule is the adjustment, not the clipping
alone (isolating every pass-through clipping base broke those two).

CPU compositor and GPU plan alike. psd-tools 239 -> 240; floor 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Empty commit to resync the pull request head

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-14 14:10:14 -04:00
Timothy Daly 620bccef42 32-bit: legacy Brightness/Contrast, Channel Mixer, Photo Filter and B&W tint unclipped, as in Photoshop (#5011)
* 32-bit: legacy Brightness/Contrast, Channel Mixer, Photo Filter and B&W tint unclipped

In 32-bit documents Photoshop keeps these adjustments' results above 1
and below 0. On the photoshop corpus's rgb32/gray32 files:
- Legacy Brightness/Contrast pivots its contrast at 127 of 255 (8/16-bit:
  128) and is exact on every pixel.
- Channel Mixer cuts each source percentage to 1/1024 toward zero, counts
  255/512 of the constant and is exact on pure red, green, blue, black
  and white.
- Photo Filter works on the linear samples, negative results included.
- The Black & White tint is the Color blend mode without the clip at 1,
  as the blend mode is there; white tints to (1.05, 1.00, 0.87).

We clipped all four to 0..1. The GPU kernels follow suit under F_HDR
(the legacy pivot and the mixer's steps come from the planner), and the
HDR parity test covers them.

Photoshop oracles: rgb32 and gray32 brightness-contrast-legacy, rgb32
channel-mixer and black-white-tint pass (145 -> 149 of 258); floor
145 -> 149. rgb32 photo-filter improves (0.19 -> 0.035 max); the rest is
its colour (#3790).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Masks: feathers blur with exactly the feather's variance

A mask feather is a Gaussian with sigma = feather, which we approximate
with three box passes per axis. Whole-pixel boxes rounded the variance:
a 6 px feather blurred like 6.48 px and a 3 px one like 3.46 px, so
feathered edges were too soft by up to 4 levels against Photoshop
(psd-tools mask-parameters-no-real-channel.psd: a 6 px vector and 3 px
pixel feather).

Each pass is now an "extended box" (Gwosdek et al. 2011): weight 1 on
the whole radius and a fractional weight on the two samples beyond it,
so three passes have variance sigma^2 exactly. It stays O(n), reusing
the window's leaving sample for the low end weight (50 MP at a 1000 px
feather: 180 ms parallel, was 172).

psd-tools: mask-parameters-no-real-channel 0.0168 -> 0.0060 (PASS),
layer_mask_data.psd 26.9 % -> 3.9 % of pixels off (psb 25.9 % -> 1.8 %).
Corpus test 239 -> 240; floor 236 -> 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Threshold: split on Photoshop's luminosity of whole samples

Photoshop's Threshold splits on the luminosity 0.30 R + 0.59 G + 0.11 B
(the blend modes' lum, as Gradient Map uses), not the Rec. 601 grey,
taken over the document's whole sample values:

- 8 bits: 30 R + 59 G + 11 B > 100 level - 50, i.e. the luminosity
  rounded to a level with halves down reaches the level;
- 16 bits: 30 R + 59 G + 11 B >= 100 x the level in 16 bits
  (round(level x 32768 / 255): mid grey 16448 is level 128);
- 32 bits: the luminosity reaches the level.

Exact on every pixel of psd-tools threshold_rgb (36432 px; Rec. 601 split
28 the other way), threshold_16bits_rgb (100) and threshold_16bits_
grayscale, and the photoshop corpus's rgb16 threshold-128. The sums are
exact in f32, on the CPU and in the GPU kernel, so ties (grey exactly on
the level) split the same way on both.

psd-tools: threshold_rgb and threshold_16bits_rgb pass; corpus test
239 -> 241, floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Posterize: 16-bit documents bin the 16-bit sample, as Photoshop does

At 16 bits Photoshop doesn't round to 8-bit levels before binning. It
bins the 16-bit sample, floor(v16 * n / 32768), and lands on 8-bit levels
through a 16-bit step: floor(b * 32768 / (n - 1)), converted with
floor((o * 255 + 16384) / 32768). So the middle of 3 levels is 128 where
8 bits give 127, while 42.5 and 25.5 stay 42 and 25.

Exact on every sample of psd-tools posterize_16bits_rgb (levels 3, 7,
13, 21) and posterize_16bits_grayscale (2, 6, 9, 11); the 8-bit rule
missed up to half the range at bin edges. The same rule applies to
CMYK and Lab channels at 16 bits: on the stored inks (#4945's native
path) psd-tools posterize_16bits_cmyk goes from 4.26 % to 0.01 % of
pixels off. 8-bit Posterize is unchanged.

The GPU kernel runs the same rule; 16-bit layers reach it as half
floats, so a sample within their precision of a bin edge can land in
the neighbouring bin there (the CPU, which exports, is exact).

psd-tools 239 -> 241; floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Groups: a pass-through clipping base with an adjustment renders isolated

A pass-through group composites its children straight into the
backdrop, so an adjustment layer inside reaches the layers beneath.
When the group is the base of a clipping group and holds an adjustment
layer, Photoshop renders it isolated instead: in psd-tools
passthrough_clipping_mask_adjustment an Exposure in such a group leaves
the layers beneath alone (we darkened them: half the image 170 levels
off). The same group with a Linear Dodge child and no adjustment keeps
reaching the backdrop (passthrough_clipping_mask_blendmode), and so do
clipping-mask3/4/5, so the rule is the adjustment, not the clipping
alone (isolating every pass-through clipping base broke those two).

CPU compositor and GPU plan alike. psd-tools 239 -> 240; floor 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-14 14:03:03 -04:00
Timothy Daly eb26e8f0d7 Masks: feathers blur with exactly the feather's variance (mask-parameters-no-real-channel passes) (#5163)
* Masks: feathers blur with exactly the feather's variance

A mask feather is a Gaussian with sigma = feather, which we approximate
with three box passes per axis. Whole-pixel boxes rounded the variance:
a 6 px feather blurred like 6.48 px and a 3 px one like 3.46 px, so
feathered edges were too soft by up to 4 levels against Photoshop
(psd-tools mask-parameters-no-real-channel.psd: a 6 px vector and 3 px
pixel feather).

Each pass is now an "extended box" (Gwosdek et al. 2011): weight 1 on
the whole radius and a fractional weight on the two samples beyond it,
so three passes have variance sigma^2 exactly. It stays O(n), reusing
the window's leaving sample for the low end weight (50 MP at a 1000 px
feather: 180 ms parallel, was 172).

psd-tools: mask-parameters-no-real-channel 0.0168 -> 0.0060 (PASS),
layer_mask_data.psd 26.9 % -> 3.9 % of pixels off (psb 25.9 % -> 1.8 %).
Corpus test 239 -> 240; floor 236 -> 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Threshold: split on Photoshop's luminosity of whole samples

Photoshop's Threshold splits on the luminosity 0.30 R + 0.59 G + 0.11 B
(the blend modes' lum, as Gradient Map uses), not the Rec. 601 grey,
taken over the document's whole sample values:

- 8 bits: 30 R + 59 G + 11 B > 100 level - 50, i.e. the luminosity
  rounded to a level with halves down reaches the level;
- 16 bits: 30 R + 59 G + 11 B >= 100 x the level in 16 bits
  (round(level x 32768 / 255): mid grey 16448 is level 128);
- 32 bits: the luminosity reaches the level.

Exact on every pixel of psd-tools threshold_rgb (36432 px; Rec. 601 split
28 the other way), threshold_16bits_rgb (100) and threshold_16bits_
grayscale, and the photoshop corpus's rgb16 threshold-128. The sums are
exact in f32, on the CPU and in the GPU kernel, so ties (grey exactly on
the level) split the same way on both.

psd-tools: threshold_rgb and threshold_16bits_rgb pass; corpus test
239 -> 241, floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Posterize: 16-bit documents bin the 16-bit sample, as Photoshop does

At 16 bits Photoshop doesn't round to 8-bit levels before binning. It
bins the 16-bit sample, floor(v16 * n / 32768), and lands on 8-bit levels
through a 16-bit step: floor(b * 32768 / (n - 1)), converted with
floor((o * 255 + 16384) / 32768). So the middle of 3 levels is 128 where
8 bits give 127, while 42.5 and 25.5 stay 42 and 25.

Exact on every sample of psd-tools posterize_16bits_rgb (levels 3, 7,
13, 21) and posterize_16bits_grayscale (2, 6, 9, 11); the 8-bit rule
missed up to half the range at bin edges. The same rule applies to
CMYK and Lab channels at 16 bits: on the stored inks (#4945's native
path) psd-tools posterize_16bits_cmyk goes from 4.26 % to 0.01 % of
pixels off. 8-bit Posterize is unchanged.

The GPU kernel runs the same rule; 16-bit layers reach it as half
floats, so a sample within their precision of a bin edge can land in
the neighbouring bin there (the CPU, which exports, is exact).

psd-tools 239 -> 241; floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Groups: a pass-through clipping base with an adjustment renders isolated

A pass-through group composites its children straight into the
backdrop, so an adjustment layer inside reaches the layers beneath.
When the group is the base of a clipping group and holds an adjustment
layer, Photoshop renders it isolated instead: in psd-tools
passthrough_clipping_mask_adjustment an Exposure in such a group leaves
the layers beneath alone (we darkened them: half the image 170 levels
off). The same group with a Linear Dodge child and no adjustment keeps
reaching the backdrop (passthrough_clipping_mask_blendmode), and so do
clipping-mask3/4/5, so the rule is the adjustment, not the clipping
alone (isolating every pass-through clipping base broke those two).

CPU compositor and GPU plan alike. psd-tools 239 -> 240; floor 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-14 14:02:40 -04:00
Timothy Daly 9954c2935e Threshold: split on Photoshop's luminosity of whole samples (threshold_rgb, threshold_16bits_rgb pass) (#5263)
* Threshold: split on Photoshop's luminosity of whole samples

Photoshop's Threshold splits on the luminosity 0.30 R + 0.59 G + 0.11 B
(the blend modes' lum, as Gradient Map uses), not the Rec. 601 grey,
taken over the document's whole sample values:

- 8 bits: 30 R + 59 G + 11 B > 100 level - 50, i.e. the luminosity
  rounded to a level with halves down reaches the level;
- 16 bits: 30 R + 59 G + 11 B >= 100 x the level in 16 bits
  (round(level x 32768 / 255): mid grey 16448 is level 128);
- 32 bits: the luminosity reaches the level.

Exact on every pixel of psd-tools threshold_rgb (36432 px; Rec. 601 split
28 the other way), threshold_16bits_rgb (100) and threshold_16bits_
grayscale, and the photoshop corpus's rgb16 threshold-128. The sums are
exact in f32, on the CPU and in the GPU kernel, so ties (grey exactly on
the level) split the same way on both.

psd-tools: threshold_rgb and threshold_16bits_rgb pass; corpus test
239 -> 241, floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Posterize: 16-bit documents bin the 16-bit sample, as Photoshop does

At 16 bits Photoshop doesn't round to 8-bit levels before binning. It
bins the 16-bit sample, floor(v16 * n / 32768), and lands on 8-bit levels
through a 16-bit step: floor(b * 32768 / (n - 1)), converted with
floor((o * 255 + 16384) / 32768). So the middle of 3 levels is 128 where
8 bits give 127, while 42.5 and 25.5 stay 42 and 25.

Exact on every sample of psd-tools posterize_16bits_rgb (levels 3, 7,
13, 21) and posterize_16bits_grayscale (2, 6, 9, 11); the 8-bit rule
missed up to half the range at bin edges. The same rule applies to
CMYK and Lab channels at 16 bits: on the stored inks (#4945's native
path) psd-tools posterize_16bits_cmyk goes from 4.26 % to 0.01 % of
pixels off. 8-bit Posterize is unchanged.

The GPU kernel runs the same rule; 16-bit layers reach it as half
floats, so a sample within their precision of a bin edge can land in
the neighbouring bin there (the CPU, which exports, is exact).

psd-tools 239 -> 241; floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Groups: a pass-through clipping base with an adjustment renders isolated

A pass-through group composites its children straight into the
backdrop, so an adjustment layer inside reaches the layers beneath.
When the group is the base of a clipping group and holds an adjustment
layer, Photoshop renders it isolated instead: in psd-tools
passthrough_clipping_mask_adjustment an Exposure in such a group leaves
the layers beneath alone (we darkened them: half the image 170 levels
off). The same group with a Linear Dodge child and no adjustment keeps
reaching the backdrop (passthrough_clipping_mask_blendmode), and so do
clipping-mask3/4/5, so the rule is the adjustment, not the clipping
alone (isolating every pass-through clipping base broke those two).

CPU compositor and GPU plan alike. psd-tools 239 -> 240; floor 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-14 14:02:26 -04:00
Timothy Daly 3feebb9b13 Groups: a pass-through clipping base with an adjustment renders isolated (passthrough_clipping_mask_adjustment passes) (#5272)
* Posterize: 16-bit documents bin the 16-bit sample, as Photoshop does

At 16 bits Photoshop doesn't round to 8-bit levels before binning. It
bins the 16-bit sample, floor(v16 * n / 32768), and lands on 8-bit levels
through a 16-bit step: floor(b * 32768 / (n - 1)), converted with
floor((o * 255 + 16384) / 32768). So the middle of 3 levels is 128 where
8 bits give 127, while 42.5 and 25.5 stay 42 and 25.

Exact on every sample of psd-tools posterize_16bits_rgb (levels 3, 7,
13, 21) and posterize_16bits_grayscale (2, 6, 9, 11); the 8-bit rule
missed up to half the range at bin edges. The same rule applies to
CMYK and Lab channels at 16 bits: on the stored inks (#4945's native
path) psd-tools posterize_16bits_cmyk goes from 4.26 % to 0.01 % of
pixels off. 8-bit Posterize is unchanged.

The GPU kernel runs the same rule; 16-bit layers reach it as half
floats, so a sample within their precision of a bin edge can land in
the neighbouring bin there (the CPU, which exports, is exact).

psd-tools 239 -> 241; floor 236 -> 241.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Groups: a pass-through clipping base with an adjustment renders isolated

A pass-through group composites its children straight into the
backdrop, so an adjustment layer inside reaches the layers beneath.
When the group is the base of a clipping group and holds an adjustment
layer, Photoshop renders it isolated instead: in psd-tools
passthrough_clipping_mask_adjustment an Exposure in such a group leaves
the layers beneath alone (we darkened them: half the image 170 levels
off). The same group with a Linear Dodge child and no adjustment keeps
reaching the backdrop (passthrough_clipping_mask_blendmode), and so do
clipping-mask3/4/5, so the rule is the adjustment, not the clipping
alone (isolating every pass-through clipping base broke those two).

CPU compositor and GPU plan alike. psd-tools 239 -> 240; floor 240.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-14 14:01:50 -04:00
Timothy Daly 8504dc615e Posterize: 16-bit documents bin the 16-bit sample, as Photoshop does (#5267)
At 16 bits Photoshop doesn't round to 8-bit levels before binning. It
bins the 16-bit sample, floor(v16 * n / 32768), and lands on 8-bit levels
through a 16-bit step: floor(b * 32768 / (n - 1)), converted with
floor((o * 255 + 16384) / 32768). So the middle of 3 levels is 128 where
8 bits give 127, while 42.5 and 25.5 stay 42 and 25.

Exact on every sample of psd-tools posterize_16bits_rgb (levels 3, 7,
13, 21) and posterize_16bits_grayscale (2, 6, 9, 11); the 8-bit rule
missed up to half the range at bin edges. The same rule applies to
CMYK and Lab channels at 16 bits: on the stored inks (#4945's native
path) psd-tools posterize_16bits_cmyk goes from 4.26 % to 0.01 % of
pixels off. 8-bit Posterize is unchanged.

The GPU kernel runs the same rule; 16-bit layers reach it as half
floats, so a sample within their precision of a bin edge can land in
the neighbouring bin there (the CPU, which exports, is exact).

psd-tools 239 -> 241; floor 236 -> 241.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
2026-10-14 14:01:01 -04:00
Valentin Klein 2d5e60ad51 Compose: build a layer's effect-map identity once per render, not once per tile (#4437) (#4438)
effect_maps hashed the whole layer (Debug of effects and vector mask, a walk
over every pixel and mask tile, every child of a group) on every call, i.e.
once per render tile per effect layer. The identity depends on the layer
only; memoise it in the render's Ctx for layers that are part of the
document being rendered (their addresses cannot be reused during the render).

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-14 12:46:51 -04:00