With a gray among the colors, an anti-aliased edge pixel of black on
white is also a mix of black and gray, or of gray and white, and the
unmixing took the mix with the smallest error, which often held the
gray. A black disc and a gray square on white traced the gray as the
square plus 8 to 24 slivers around the disc, with the colors found or
named exactly.
When another mix of two classes also reproduces an edge pixel, the pixel
now takes it if that mix's classes lie nearer in the flat areas around
the pixel and the pixel has a neighbor on each side of the left-out
class, along the line between the other two. Pixels within a few levels
of a class outside a flat area are checked the same way, and they now
count toward the number of pixel values that decides when a busy image
is averaged down further. A flat area that stands for no class, as with
colors named some levels off, counts as holding the classes of its mix,
and so do the pixels of exactly its color joined to it. Whether a
hard-edged image is softened is still judged from each pixel's best mix.
The slivers are removed around sharp edges and edges blurred by up to
about half a pixel; an edge blurred by a pixel or more, or pixel noise
of a level or more, can still leave some. Gray strokes two and three
pixels wide beside black stay gray, and so does a one-pixel gray line
between black and white of at least 13 joined pixels. These trace as
black and white: a shorter one-pixel line, or one that falls between
pixels or is blurred; a soft-edged gray stroke about two pixels wide
touching black; and most or all of a soft-edged stroke about three
pixels wide touching black, 12 pixels long or less.
Docs: docs/image-trace-adjustments.md, docs/target-app-parity.md.
An Overlapping layer covers the colors above it within its area, so an
area of another color that a shape enclosed was a hole in that shape
and in the shape of every layer around it, and its outline was fitted
once for each of them. In a code-drawn test, a white disc in a black
ring that four grays touch had six copies of its outline.
With Fills and without Create Strokes, each shape is now filled whole,
by a fill rule of VectorCraft's own. The area inside a filled hole is
traced on its own and drawn after the shapes around it, so its outline
is fitted once. An area of one color is drawn from the hole's outline.
A shape keeps a hole where the area holds a transparent pixel or a
color that Ignore Color or Keep Colors leaves out, and a hole smaller
than Noise is filled with the shape's color as before. Nested areas are
traced within a work budget of VectorCraft's own: four times the
image's pixels (counted as at least 65,536) times its colors, each area
costing its box times its colors. An area that costs more than what is
left keeps its holes and is not charged. Create Strokes and outlines
without Fills are unchanged.
Shapes have holes only in those cases, there are more paths, and the
stacking order changes. Expand by Color starts another group of a color
where an area is drawn above the shape around it. The trace's progress
counts finer steps across the rounds of enclosed areas, not one step
per color layer.
A layer's components without its own color are now left out after its
mask is traced, instead of in a labeling pass before it. Every route
finds its components through the same function.
With logoColors named, Flat Logo measured how flat the image is against
the named colors. A solid pixel counts as flat only within 22 (RGB
distance) of one of those colors or white. Flat art whose named colors
were 20 levels off in every channel was refused as not flat, and the
refusal score of a gradient changed with the names.
The check now uses the image's own colors, found the same way as when
no colors are named. It looks for as many colors as are named, with
white, or as the Colors setting gives, whichever is more. How far the named colors are
from the image's colors no longer changes whether the image is refused.
This changes one existing behavior: an image with large areas of a
color that was not named used to be refused, and it is now traced in
the named colors.
Docs: docs/image-trace-adjustments.md, docs/target-app-parity.md, the
imageTrace.make params text.
With Document Swatches as the library, traced fills and strokes take the
library color without a swatch link. Global, spot and tint swatches no
longer link the trace, so editing a swatch later leaves the trace
unchanged, and swatch order no longer decides whether a fill is linked.
Each region still takes the nearest library color, and a tint traces at
the color the tint swatch shows.
When a process swatch listed before a global or spot swatch showed the
same color, a traced fill of that color took the process swatch and
stayed unlinked. Of the swatches that trace as one color, the first
linked one now gives the fill, and the first one otherwise.
Tracing a photo or a large image ran inside imageTrace.make on the UI
thread, so the window froze for as long as the trace took, with nothing
to say it was working.
A trace the user asks for (Object > Image Trace > Make and Make and
Expand, the task bar's Image Trace, the Image Trace panel's Trace and
presets) now runs on a thread of its own, as heavy plug-in filters do.
The status bar says so, and after 0.4 s a progress window shows how
many of the image's colors are traced, with Cancel and Continue in
Background (imageTrace.cancelRuns, imageTrace.hideRuns).
The result goes back to the command it was prepared for
(cmd::TraceRun, Traced::hand_in), which takes it only for the same
object, image and settings, so the edit is one undo step as before. A
newer trace of the same object replaces one still running, and a trace
whose image or settings changed meanwhile changes nothing. The control
channel, MCP, scripts and the web trace at once, as before.
The tracer reports its stages and color layers to a callback and stops
when it says so (trace_watched).
With the Document Library palette, each pixel took the library color
nearest in plain Oklab distance. A 50% gray lies nearer in that distance
to a saturated blue of the same lightness than to black or a light
cream, and a muted brown is also nearer to the blue than to either. With
a black, cream and blue library, both traced as the blue.
This changes how Document Library matches pixels: each pixel now takes
the library color nearest with differences in hue and chroma (Oklab a
and b) counted three times as much as lightness. The same measure picks
which library colors are used. Neutral and muted tones take a neutral
library color, and the other palettes are unchanged.
With Method Abutting, neighboring colors share one exact edge. The canvas
smooths each path's edges on its own, so each path covers only part of the
pixels along that edge, and a thin line of the background can show between
the colors. The adjustments page did not say so. It now describes the line,
names the default and the presets that use Abutting (Default, Auto Color,
3 Colors, 6 Colors and 16 Colors), says which exports show it (SVG and PDF
in most viewers; raster exports with Type Optimized, or with Art Optimized
above 10 million pixels or 16,384 pixels on a side), and points to
Overlapping, which stacks the colors and shows no background along shared
edges.
Flat Logo traces a copy of the image at most 1024 pixels on a side,
averaged down by a whole factor, so a 1025-pixel image is traced at
513 pixels. The trace's warnings did not say so, because they compared
the image only with the decoded raster. For an image over 1500 pixels
they said instead that it is traced more slowly, which Flat Logo does
not do.
The trace result now carries Flat Logo's working size when it averaged
the image down. imageTrace.make and imageTrace.makeAndExpand then name
both sizes in their warnings, and the status bar shows that note, in
place of the slower-trace and megapixel notes. Other modes keep their
warnings. The message has a row in each catalog that translates the
other Image Trace warnings.
A trace whose kept colors were traced and produced no paths gave no
warning, or, with Ignore Color on, said that Ignore Color left those
colors out. The Ignore Color warning now shows only when no kept color
was traced at all, and otherwise the first warning says that the colors
that match keepColors produce no paths. The new message has a row in
each complete-message catalog.
Whether Ignore Color or keepColors leaves a palette entry out is now
decided once per entry, so tracing a layer no longer scans the
keepColors list for each pixel.
Docs: docs/image-trace-adjustments.md.
Image Trace had no way to trace some of an image's colors and leave the
rest out. Ignore Color drops one color, so tracing only the line work of
a multi-color image took a full trace and then deleting the other
colors' paths by hand.
With "keepColors": ["#rrggbb", ...] in the params of imageTrace.make and
imageTrace.makeAndExpand, only the palette colors within about 30 levels
of a listed color are traced, the distance Ignore Color matches by. With
Method Abutting, the kept colors' paths are the same as in a trace of
every color. With Method Overlapping, a kept color's paths do not reach
under the colors left out, as with Ignore Color. An empty list traces
every color, and a value that is not a six-digit hex color is refused.
Flat Logo mode does not use the list.
The reply's warnings name each listed color that matches none of the
colors the trace found, and say when nothing was traced; the status bar
shows the first. The warnings are translated in every complete catalog.
The params help of imageTrace.make lists keepColors and the new
warnings, and the help of imageTrace.makeAndExpand lists the warnings
it returns.
The Automatic palette counts flat art's colours by area (a colour needs
about 1% of the picture, 0.5% at Colors 100) and fits that count with
median cut and area-weighted k-means. A stem, a highlight, or a near
white beside a pale background (within 24 levels, so in one box) was
averaged into a large neighbour; mixed-colour merging and Noise could
then remove what was left.
On the flat route only, after the count is fitted, rare_colours finds
the colours too rare or too close for it and keeps those that are
distinct (at least 2.5 in Oklab x 100 from every palette colour and from
the main colour each stands for), flat (mostly one histogram bin) and
drawn (a 4-connected region of their own unblended pixels of at least 8
pixels, or three of at least 4); a colour lying between two others, as
anti-aliasing mixes them, must also have an inside. At most six, largest
region first. They stay fixed while the other colours are refitted
around them; merge_mixed leaves them alone; denoise_keeping keeps their
regions of 4 pixels or more whatever Noise is (smaller specks still go).
Full Tone, Limited and Automatic's continuous-tone route are unchanged,
and denoise without kept labels is as before.
Methods cited in the code: median cut (Heckbert 1982), k-means (Lloyd
1982), Oklab (Ottosson 2020), salient-colour preservation (Fukuda et al.
2019, doi:10.1117/12.2521607). The rule and its numbers are VectorCraft's
own; Adobe does not document how its palettes are chosen.
Tests (code-drawn): a rare stem or patch over 2-8 flat colours, hard
and anti-aliased at 1x and 2x; near-white highlights on #FFF4E0 kept and
still paths at Noise 16; a 3 px #909090 stem on #808080; scattered
single pixels of the same areas add no colour; denoise_keeping at Noise
0-32.
Measured on 66 synthetic flat logos (22 designs x hard 1x, anti-aliased
1x and 2x; local inputs): every key colour and no spurious one in 66
(was 39); missing key colours 0 (was 43), spurious 0 (was 2), merged
pairs 0 (was 46); rendered dE00 0.348 -> 0.138. Four public-domain scan
crops take the continuous-tone route and are unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018tBcdwNhptqtmX32JCGFzB
The public documentation says Image Trace warns about images larger
than 1500 pixels on a side but traces them, only more slowly. VectorCraft
traced them silently, and refused any trace of more than 2,000,000
anchors, which a 4000 x 3000 photo at High Fidelity Photo nearly reaches
(1.9 million on a code-drawn photo) and a noisier one passes.
- imageTrace.make and makeAndExpand return `warnings`: one for an image
over 1500 px on a side (traced, but more slowly; a lower-fidelity
preset or a smaller copy is quicker), one for an image over 64 MP
that was traced from a scaled-down copy. The app shows the first in
the status bar.
- MAX_TRACE_ANCHORS is 8,000,000 natively (2,000,000 on wasm, where a
page has at most 4 GB). Measured through imageTrace.make on
code-drawn photos: about 90 bytes an anchor kept in the document;
7.9 million anchors kept 685 MB with an 876 MB peak (4000 x 3000,
Full Tone at Colors 100, Paths 100, Noise 1, 37 s).
- The refusal keeps its translated advice: raise Noise, lower Paths or
Colors, or pick a lower-fidelity preset.
Tests: a_large_image_traces_with_a_warning (1600 x 40 and 1500 x 8
code-drawn images, make and make-and-expand),
trace_warnings_name_a_large_or_scaled_down_image, a compile-time check
of the limit's range, and a UI test that the status bar shows the note.
Source:
https://helpx.adobe.com/illustrator/using/image-trace-results-optimization.html
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018tBcdwNhptqtmX32JCGFzB
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