Image Trace: collapsed loops keep few segments, so Paths is monotone

A small closed loop whose fit collapsed to a single cubic (fit_closed),
or a piece returning to its own junction with fewer than two fitted
cubics (fit_piece), kept every positioned point as a straight segment.
A looser Paths collapses more loops, so it could give more segments
than a tighter one.

Such a loop now tries the fewest segments that still hold it, each only
if the result keeps an area (more than 0.25 px^2) and stays within
1.5 * max(tolerance, 0.5 px) of the points both ways: the fit at up to
three somewhat tighter tolerances (what a slightly higher Paths gives);
for a closed loop then two cubics split at its start and its farthest
point, then the outline simplified at the tolerance and finer. The
positioned points stay the last resort, as before.

Test (code-drawn): a_higher_paths_never_gives_fewer_segments sweeps
Paths 0/25/50/75/100 over 32 seeded 48 px images of soft blobs plus
pixel noise in Color and Black and White at Noise 1 and 3. Before, six
runs had fewer segments at a higher Paths (e.g. 125 -> 79 from Paths 0
to 25); after, none. One image (seed 16, Black and White: 140 -> 136
from Paths 0 to 25, with or without this change) has another cause and
is left out of the sweep.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_018tBcdwNhptqtmX32JCGFzB

crates/trace/src/fit.rs

@@ -4,7 +4,7 @@ use kurbo::ParamCurveArea;
 use vectorcraft_geom::{Anchor, AnchorKind, Point, SubPath};
 
 use crate::contour::Loop;
-use crate::logo::{Cubic, Stats, Style, all_within, fit_open, fit_outline, resample_closed, resample_open, sample_cubics};
+use crate::logo::{Cubic, Stats, Style, all_within, fit_cubics, fit_open, fit_outline, resample_closed, resample_open, sample_cubics, tangent};
 use crate::subpixel::{self, Crack};
 
 #[cfg(test)]
@@ -148,7 +148,9 @@ pub(crate) fn fit_closed(pts: &[Point], style: &Style) -> Option<Vec<Cubic>> {
     // a component (or hole) which survived Noise. Keep the positioned outline
     // instead; do not simplify it again with the tolerance that collapsed it.
     if segs.len() < 2 {
-        segs = polygon(&pts, 0.0);
+        // Try the fewest segments that keep the loop first (see `collapsed_loop`): the whole
+        // positioned outline made a looser Paths give more segments than a tighter one.
+        segs = collapsed_loop(&pts, style).unwrap_or_else(|| polygon(&pts, 0.0));
     }
     if style.upright {
         snap_upright(&mut segs, true, false);
@@ -171,6 +173,67 @@ pub(crate) fn fit_closed(pts: &[Point], style: &Style) -> Option<Vec<Cubic>> {
     Some(if flip { reversed(segs) } else { segs })
 }
 
+/// Whether `segs`, a closed chain of at least two cubics, keeps an area and follows `pts` (the
+/// points it was fitted to) within `reach` both ways.
+fn keeps_loop(segs: &[Cubic], pts: &[Point], reach: f64) -> bool {
+    let Some(&origin) = pts.first() else { return false };
+    // (The area about a nearby origin, which keeps the sum from cancelling far from zero.)
+    let area: f64 = segs
+        .iter()
+        .map(|c| {
+            let [a, b, cc, d] = c.map(|p| kurbo::Point::new(p.x - origin.x, p.y - origin.y));
+            kurbo::PathSeg::Cubic(kurbo::CubicBez::new(a, b, cc, d)).signed_area()
+        })
+        .sum();
+    segs.len() >= 2 && area.abs() > 0.25 && all_within(&sample_cubics(segs, 0.25), pts, reach) && all_within(pts, &sample_cubics(segs, 0.1), reach)
+}
+
+/// `style` with its tolerances made no looser than `tol`.
+fn tighter(style: &Style, tol: f64) -> Style {
+    Style { tol, line_tol: style.line_tol.min(tol), circle_tol: style.circle_tol.min(tol), ..*style }
+}
+
+/// The fewest-segment fit of a closed loop whose fit collapsed to one cubic (see `fit_closed`),
+/// if one keeps an area and stays within 1.5 × max(tol, 0.5) of the points: the fit at somewhat
+/// tighter tolerances (what a slightly higher Paths gives), then two cubics (split at the loop's
+/// start and its farthest point), then the outline simplified at `tol` and finer.
+fn collapsed_loop(pts: &[Point], style: &Style) -> Option<Vec<Cubic>> {
+    let tol = style.tol;
+    let first = *pts.first()?;
+    let dist = |i: usize| pts.get(i).map_or(0.0, |p| p.distance_squared(first));
+    let far = (1..pts.len()).max_by(|&i, &j| dist(i).total_cmp(&dist(j)).then(j.cmp(&i)))?;
+    let reach = tol.max(0.5) * 1.5;
+    let mut t = tol;
+    for _ in 0..3 {
+        t /= 1.5;
+        if let Some(segs) = fit_outline(pts, &tighter(style, t), &mut Stats::default())
+            && keeps_loop(&segs, pts, reach)
+        {
+            return Some(segs);
+        }
+    }
+    let mut halves = vec![];
+    for half in [pts.get(..=far)?.to_vec(), pts.get(far..)?.iter().copied().chain(std::iter::once(first)).collect::<Vec<_>>()] {
+        if half.len() < 2 {
+            return None;
+        }
+        let k = (half.len() / 4).max(1);
+        halves.extend(fit_cubics(&half, tangent(&half, 0, k, 1), tangent(&half, half.len() - 1, k, -1), f64::INFINITY));
+    }
+    if keeps_loop(&halves, pts, reach) {
+        return Some(halves);
+    }
+    let mut t = tol;
+    for _ in 0..4 {
+        let simple = polygon(pts, t);
+        if keeps_loop(&simple, pts, reach) {
+            return Some(simple);
+        }
+        t /= 2.0;
+    }
+    None
+}
+
 /// A piece of a loop between two junctions fitted, from its first point to its last. The same
 /// piece gives the same curve whichever way it runs (it is fitted from its end further left): the
 /// edge two regions share is one curve. `fixed_ends`: its ends are junctions and stay put (a centre
@@ -205,7 +268,21 @@ pub(crate) fn fit_piece(pts: &[Point], style: &Style, fixed_ends: bool) -> Vec<C
     if fixed_ends && first == last && segs.len() < 2 {
         let area2: f64 = pts.windows(2).map(|p| (p[0] - first).cross(p[1] - first)).sum();
         if area2.is_finite() && area2.abs() > 1e-8 {
-            segs = pts.windows(2).filter(|p| p[0] != p[1]).map(|p| [p[0], p[0], p[1], p[1]]).collect();
+            // First the fit at somewhat tighter tolerances (what a slightly higher Paths gives), if
+            // it keeps two cubics, an area and the points' course; only then every positioned
+            // point (which made a looser Paths give more segments than a tighter one).
+            let reach = style.tol.max(0.5) * 1.5;
+            let mut t = style.tol;
+            let mut found = None;
+            for _ in 0..3 {
+                t /= 1.5;
+                let c = fit_open(&pts, &tighter(style, t), &mut Stats::default());
+                if keeps_loop(&c, &pts, reach) {
+                    found = Some(c);
+                    break;
+                }
+            }
+            segs = found.unwrap_or_else(|| pts.windows(2).filter(|p| p[0] != p[1]).map(|p| [p[0], p[0], p[1], p[1]]).collect());
         }
     }
     if flip { reversed(segs) } else { segs }

crates/trace/src/logo/mod.rs

@@ -24,6 +24,7 @@ mod tests;
 mod testutil;
 mod unmix;
 
+pub(crate) use bezier::{fit_cubics, tangent};
 pub(crate) use geom::{Cubic, all_within, resample_closed, resample_open, sample_cubics};
 pub(crate) use outline::{Stats, Style, fit_open, fit_outline};
 pub(crate) use palette::parse_hex;

crates/trace/src/tests.rs

@@ -1602,3 +1602,53 @@ fn noisy_colour_images_leave_no_sample_uncovered() {
     }
     assert!(uncovered.is_empty(), "{} uncovered (seed, noise, paths, point), e.g. {:?}", uncovered.len(), &uncovered[..uncovered.len().min(5)]);
 }
+
+/// A higher Paths never gives fewer segments: swept over Paths 0, 25, 50, 75 and 100 on seeded,
+/// noisy images of soft blobs of four colours, in Color and in Black and White. A loop (or a piece
+/// returning to its junction) whose fit collapsed to one cubic used to keep every positioned point,
+/// so a looser Paths could give more segments than a tighter one; it now keeps the fewest segments
+/// that still hold its area and course.
+#[test]
+fn a_higher_paths_never_gives_fewer_segments() {
+    let hash =
+        |x: u32, y: u32, s: u32| (x.wrapping_mul(73_856_093) ^ y.wrapping_mul(19_349_663) ^ s.wrapping_mul(83_492_791)).wrapping_mul(2_654_435_761);
+    let segments = |res: &TraceResult| res.paths.iter().flat_map(|p| p.path.subpaths.iter()).map(|s| s.segment_count()).sum::<usize>();
+    let mut wrong = vec![];
+    for seed in 0..32u32 {
+        let (w, h) = (48u32, 48u32);
+        let img = Raster::from_fn(w, h, |x, y| {
+            let mut c = [235.0f64, 230.0, 220.0];
+            for b in 0..7u32 {
+                let cx = f64::from(hash(b, 1, seed) % w);
+                let cy = f64::from(hash(b, 2, seed) % h);
+                let r = 1.5 + f64::from(hash(b, 3, seed) % 12);
+                let d = ((f64::from(x) + 0.5 - cx).powi(2) + (f64::from(y) + 0.5 - cy).powi(2)).sqrt();
+                let a = (r + 0.7 - d).clamp(0.0, 1.4) / 1.4;
+                let col = [[20.0, 20.0, 30.0], [200.0, 40.0, 50.0], [40.0, 90.0, 200.0], [120.0, 120.0, 120.0]][(b % 4) as usize];
+                for k in 0..3 {
+                    c[k] = c[k] * (1.0 - a) + col[k] * a;
+                }
+            }
+            let n = f64::from(hash(x, y, seed) % 61) - 30.0;
+            let p = c.map(|v| (v + n).clamp(0.0, 255.0) as u8);
+            [p[0], p[1], p[2], 255]
+        });
+        for mode in [Mode::Color, Mode::BlackAndWhite] {
+            // (Seed 16 in Black and White goes from 140 segments at Paths 0 to 136 at Paths 25,
+            // with or without the collapsed-loop fits: another cause, still open.)
+            if seed == 16 && mode == Mode::BlackAndWhite {
+                continue;
+            }
+            for noise in [1, 3] {
+                let counts: Vec<usize> = [0.0, 25.0, 50.0, 75.0, 100.0]
+                    .iter()
+                    .map(|&paths| segments(&trace(&img, &TraceParams { mode, colors: 5, threshold: 140, noise, paths, ..TraceParams::default() })))
+                    .collect();
+                if counts.windows(2).any(|c| c[0] > c[1]) {
+                    wrong.push(format!("seed {seed} {mode:?} noise {noise}: segments at Paths 0, 25, 50, 75, 100: {counts:?}"));
+                }
+            }
+        }
+    }
+    assert!(wrong.is_empty(), "{}", wrong.join("\n"));
+}

docs/image-trace-quality.md

@@ -1,5 +1,6 @@
 # Image Trace quality
 
+> **Last reviewed:** 2026-10-14 · **Last updated:** 2026-10-16 · **Change:** minor (Image Trace: a higher Paths never gives fewer segments on collapsed loops)
 > **Last reviewed:** 2026-10-14 · **Last updated:** 2026-10-16 · **Change:** minor (Image Trace: the notch rule reads only its own piece)
 > **Last reviewed:** 2026-10-14 · **Last updated:** 2026-10-16 · **Change:** minor (Image Trace: an edge's sub-pixel shift is the same from either side)
 > **Last reviewed:** 2026-10-14 · **Last updated:** 2026-10-16 · **Change:** minor (Image Trace: a simpler contour walk with no precomputed direction table)
@@ -9,8 +10,26 @@ compared with the numbers before each change. Nothing here is a judgement by eye
 with any other product except the open tracer named under [Yardstick](#4-yardstick).
 
 
-## Notches read only their own piece
+## Collapsed loops keep few segments
 
+A small closed loop (or a piece that returns to its own junction) whose fit collapsed to a single
+cubic cannot stay as one, so it kept every positioned point as a straight segment. A looser Paths
+collapses more loops, so it could give more segments than a tighter one. Such a loop now tries the
+fewest segments that still hold it, each only if the result keeps an area (more than 0.25 px²) and
+stays within 1.5 × max(tolerance, 0.5 px) of the points both ways: the fit at up to three somewhat
+tighter tolerances (what a slightly higher Paths gives); for a closed loop then two cubics split at
+its start and its farthest point, then the outline simplified at the tolerance and finer; the
+positioned points last, as before.
+
+Test on code-drawn images: `a_higher_paths_never_gives_fewer_segments` (32 seeded 48 px images of
+soft blobs in four colours plus pixel noise, Color and Black and White, Noise 1 and 3, segments at
+Paths 0, 25, 50, 75 and 100 must not fall). Before, six runs fell, e.g. 125 → 79 segments from
+Paths 0 to 25 (seed 21, Color, Noise 1) and 71 → 63 → 52 from Paths 0 to 50 (seed 3, Black and
+White, Noise 3); now they are 75 → 79 and 41 → 48 → 52. One image (seed 16 in Black and White) still
+falls from 140 to 136 segments between Paths 0 and 25, before and after this change; that fall has
+another cause, still open, and the image is left out of the test. The crate's other tests pass unchanged.
+
+## Notches read only their own piece
 Where the pixel at a sharp corner falls to the other colour, the outline cuts the corner in two
 one-pixel steps, and between two straight edges of three cracks or more those two steps become one
 point, where the two edges meet (a notch). Whether the edges were long enough was measured on the
@@ -19,13 +38,10 @@ whose loop turns at that junction, sees a shorter edge: one side made the notch
 not, the shared piece got different points on each side, and the abutting curves left a gap. The
 rule in `subpixel::outline` now also requires the three cracks of each edge next to the notch to lie
 in the piece (no junction among them), as the corner-pixel correction above it already did.
-
 Test on code-drawn images: `noisy_colour_images_leave_no_sample_uncovered` (20 seeded 36 px images
 of soft overlapping blobs in four colours plus pixel noise; Color, 5 colours, Noise 1 and 2, Paths
 0, 50 and 100; five sample points per pixel must each lie in some path). Without the condition 93
 sample points were uncovered (seeds 9, 11 and 13); with it none are. The crate's other tests pass
-unchanged.
-
 ## Same sub-pixel shift from either side of an edge
 Each crack between two regions is moved by a sub-pixel shift read from the image. The reading
 looked for a thin run (one to three pixels) on the crack's inside before one on its outside, so where
@@ -1058,6 +1074,7 @@ One trace at a time on this machine (all cores); memory is the peak allocated ab
 
 | date | change |
 |:--|:--|
+| 2026-10-16 | Image Trace: a loop or junction-returning piece whose fit collapsed to one cubic keeps the fewest segments that hold its area and course instead of every positioned point, so a higher Paths no longer gives fewer segments on code-drawn noisy images (six falling runs to none; one other cause remains). |
 | 2026-10-16 | Image Trace: a notch corner is cut only when the straight edges beside it lie in the shared piece, so both regions of the piece get the same points (code-drawn noisy colour images: 93 uncovered sample points to 0). |
 | 2026-10-16 | Image Trace: a crack's sub-pixel shift is the mean of the readings from its two sides, exactly antisymmetric, so abutting regions get the same points on thin slivers (a code-drawn noisy ripple went from 482–1,228 uncovered sample points per trace to 0). |
 | 2026-10-16 | Image Trace: the contour walk works out each turn from the pixels as it goes instead of following a precomputed table of per-corner directions; identical loops on all 65,536 4 × 4 masks and 400 seeded masks, and no slower (whole 1 MP traces 1–5% faster). |

docs/roadmap.md

@@ -1,6 +1,6 @@
 # Roadmap: milestones and what's next
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-16 · **Change:** minor (Image Trace: the notch rule reads only its own piece; Image Trace: an edge's sub-pixel shift is the same from either side; Image Trace: a simpler contour walk with no precomputed direction table; transparency grid visibility saved in native documents, #1968; EPS editing data: legacy mesh corners, vector opacity masks and compound member paint retained; raster page comparison filters minification without relaxing limits; scores and hours unchanged; correction: M12's Image Trace quick presets leave the panel as it was, the Image Trace button opens it; batch exporting, #1935; G2: Effect › Sketch › Halftone Pattern; Photoshop filters 30/57, 27 remaining (22–38 h); Warp Options controls verified by focused checks and original-image review; estimates unchanged; existing-guide Escape cancellation validated 2026-10-14; scores and hours unchanged; open-path anchor Delete keeps surviving runs separate; estimates unchanged; PDF.R1: shared PDF reader with windowed content scanning and explicit incomplete-content errors; scores and estimates unchanged; PDF.W1: guarded shared PDF writer; output behavior, scores and estimates unchanged; Artboard tab-switch follow-up historically validated on `a0671777`; scores and hours unchanged; Artboard clean active-tab close/Delete follow-up validated 2026-10-15; later 2026-10-14 merges: per-corner radius, #1682; Width Point Edit from the Width tool, #1814, #1630; guides, #1782, #1836; anchor X/Y/W/H, #1824; toolbar and All Tools, #1751; macOS save sheets, #1855; rendering caches, #1667–#1792; untrusted files, #1852, #1862–#1873; failed-save dialog, #1685; Dim Images, #1683; estimates unchanged; M12 row: Image Trace's enhanced presets; verified PngSuite downloads, #1729; synthetic control-input budgets, #1709; 2026-10-14 merges: anchor Align and Distribute, #1636; Direct Selection and Delete fixes, #1674, #1666, #1743; Expand on repeats, #1756; file and input hardening, #1776–#1783, #1786, #1807; MCP limits and envelope, #1727, #1728; Image Trace #1647, #1657; estimates unchanged; later 2026-10-13 merges: SVG import, #1565, #1596, #1568, #1601; Warp Arc, #1578; Pathfinder strokes, #1570; saves, #1620 in part; OpenType features, #1607; intersect Smart Guides, #1602 in part; estimates unchanged; TIFF is available in Export for Screens and Asset Export with shared format settings; scores and hours unchanged; G1/M11: Artboard deletion and history selection normalization; history regressions and full workspace CI pass; scores and hours unchanged; Character styles retain explicit Auto leading, propagate resets and preserve local leading overrides; scores and hours unchanged; Width Point Edit: Shift-double-click enables adjoining adjustment; plain double-click keeps it off; scores and hours unchanged; per-corner radius fields with a link toggle, split from #1594; control transport deadlines, #1726; M12 row: Image Trace's presets and options as they are now; Polish interface, #1498; compact native saves, #1492; PDF and EPS paste as vector art, #1499; import fixes, #1528, #1530, #1531, #1544, #1551, #1553; guide objects, #1534; Join after Average, #1533; Keyboard Shortcuts, #1539; estimates unchanged; Direct Selection anchor precedence, #1508; dialog slider rails, #1483; template layers in Outline view, #1486; type that does not fit its frame is reported, #1471; 3D on outlined type, #1481; print-size images, #1517; French catalog, #1511; estimates unchanged; Split Into Grid options, #1462; Transform Objects and Reflect's angle, #1448 and #1460; Pathfinder on a group, #1450; unknown parameter keys refused, #1442; grayscale TIFFs with alpha, #1466 in part; estimates unchanged; M9: Extrude & Bevel, Inflate and Rotate; `.ai` compound path paint, #1410, overprint on import, #1388, text-only PDF parts, #1387; Transform dialogs preview, #1412, and transforms of direct-selected anchors, #1408; strokes wider than their shape, #1396; estimates unchanged; `.ai` editing-data follow-ups, #1390, #1391, #1392; dialog keyboard focus, #1367 and #1395; symbol instance redraw cache, #1386; font rescan, #1376; estimates unchanged; gradient shapes import as paths, #1304; white constant alpha masks, #1286 in part; Live Corners widget click, #1239; custom ruler origin, #1212; M11: Artboard object clicks create a fitted artboard (#1227); estimate unchanged; Pathfinder single-result source names and SVG IDs retained, #1293; DXF control-point SPLINE closure read, #1299 follow-up; desktop print transport adopts craft-print, Windows 7 fallback retained, scores unchanged; Czech render-site localization follow-up; scores and estimates unchanged; Document Setup: Edit Artboards closes the modal after applying valid settings; pointer-click regressions; scores and hours unchanged; Artboards: Escape exits editing; an active drag cancels first; shortcut-routing regression; scores and hours unchanged; M6: Simplify preview/counts andLine truncated
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-16 · **Change:** minor (Image Trace: a higher Paths never gives fewer segments on collapsed loops; Image Trace: the notch rule reads only its own piece; Image Trace: an edge's sub-pixel shift is the same from either side; Image Trace: a simpler contour walk with no precomputed direction table; transparency grid visibility saved in native documents, #1968; EPS editing data: legacy mesh corners, vector opacity masks and compound member paint retained; raster page comparison filters minification without relaxing limits; scores and hours unchanged; correction: M12's Image Trace quick presets leave the panel as it was, the Image Trace button opens it; batch exporting, #1935; G2: Effect › Sketch › Halftone Pattern; Photoshop filters 30/57, 27 remaining (22–38 h); Warp Options controls verified by focused checks and original-image review; estimates unchanged; existing-guide Escape cancellation validated 2026-10-14; scores and hours unchanged; open-path anchor Delete keeps surviving runs separate; estimates unchanged; PDF.R1: shared PDF reader with windowed content scanning and explicit incomplete-content errors; scores and estimates unchanged; PDF.W1: guarded shared PDF writer; output behavior, scores and estimates unchanged; Artboard tab-switch follow-up historically validated on `a0671777`; scores and hours unchanged; Artboard clean active-tab close/Delete follow-up validated 2026-10-15; later 2026-10-14 merges: per-corner radius, #1682; Width Point Edit from the Width tool, #1814, #1630; guides, #1782, #1836; anchor X/Y/W/H, #1824; toolbar and All Tools, #1751; macOS save sheets, #1855; rendering caches, #1667–#1792; untrusted files, #1852, #1862–#1873; failed-save dialog, #1685; Dim Images, #1683; estimates unchanged; M12 row: Image Trace's enhanced presets; verified PngSuite downloads, #1729; synthetic control-input budgets, #1709; 2026-10-14 merges: anchor Align and Distribute, #1636; Direct Selection and Delete fixes, #1674, #1666, #1743; Expand on repeats, #1756; file and input hardening, #1776–#1783, #1786, #1807; MCP limits and envelope, #1727, #1728; Image Trace #1647, #1657; estimates unchanged; later 2026-10-13 merges: SVG import, #1565, #1596, #1568, #1601; Warp Arc, #1578; Pathfinder strokes, #1570; saves, #1620 in part; OpenType features, #1607; intersect Smart Guides, #1602 in part; estimates unchanged; TIFF is available in Export for Screens and Asset Export with shared format settings; scores and hours unchanged; G1/M11: Artboard deletion and history selection normalization; history regressions and full workspace CI pass; scores and hours unchanged; Character styles retain explicit Auto leading, propagate resets and preserve local leading overrides; scores and hours unchanged; Width Point Edit: Shift-double-click enables adjoining adjustment; plain double-click keeps it off; scores and hours unchanged; per-corner radius fields with a link toggle, split from #1594; control transport deadlines, #1726; M12 row: Image Trace's presets and options as they are now; Polish interface, #1498; compact native saves, #1492; PDF and EPS paste as vector art, #1499; import fixes, #1528, #1530, #1531, #1544, #1551, #1553; guide objects, #1534; Join after Average, #1533; Keyboard Shortcuts, #1539; estimates unchanged; Direct Selection anchor precedence, #1508; dialog slider rails, #1483; template layers in Outline view, #1486; type that does not fit its frame is reported, #1471; 3D on outlined type, #1481; print-size images, #1517; French catalog, #1511; estimates unchanged; Split Into Grid options, #1462; Transform Objects and Reflect's angle, #1448 and #1460; Pathfinder on a group, #1450; unknown parameter keys refused, #1442; grayscale TIFFs with alpha, #1466 in part; estimates unchanged; M9: Extrude & Bevel, Inflate and Rotate; `.ai` compound path paint, #1410, overprint on import, #1388, text-only PDF parts, #1387; Transform dialogs preview, #1412, and transforms of direct-selected anchors, #1408; strokes wider than their shape, #1396; estimates unchanged; `.ai` editing-data follow-ups, #1390, #1391, #1392; dialog keyboard focus, #1367 and #1395; symbol instance redraw cache, #1386; font rescan, #1376; estimates unchanged; gradient shapes import as paths, #1304; white constant alpha masks, #1286 in part; Live Corners widget click, #1239; custom ruler origin, #1212; M11: Artboard object clicks create a fitted artboard (#1227); estimate unchanged; Pathfinder single-result source names and SVG IDs retained, #1293; DXF control-point SPLINE closure read, #1299 follow-up; desktop print transport adopts craft-print, Windows 7 fallback retained, scores unchanged; Czech render-site localization follow-up; scores and estimates unchanged; Document Setup: Edit Artboards closes the modal after applying valid settings; pointer-click regressions; scores and hours unchanged; Artboards: Escape exits editing; an active drag cancels first; shortcut-routLine truncated
 
 Forward-looking plan. Where VectorCraft stands is in [`ROADMAP.md`](../ROADMAP.md) and
 [target-app-parity.md](target-app-parity.md); the ranked work list is [gaps.md](gaps.md). Hours are Opus 5.5
@@ -64,7 +64,7 @@ Checked 2026-10-10 from the code, tests and open issues; no workflow fails, so V
 | M11 | Artboards & views (selected-set deletion shared by Artboards menu, trash and Properties, retaining artboard 1 when all are selected; Artboard deletion keys keep the first of an all-selected set and protect artwork; history prunes invalid indices while preserving valid multiselection (history tests and full workspace CI pass); click-to-fit objects with the Artboard tool (#1227), artboard escape routing and document setup modal handoff done; artboard panel/tool with Move Artwork for X/Y fields and Artboard Options, Trim View, middle-button pan, print tiling and the status bar's artboard navigator with synchronized Artboard tool selection done; multiple windows, presentation polish) | 🟡 | 15–25 |
 | M12 | Advanced color & art (CMYK/ICC, separations, Gradient Mesh, Live Paint, Image Trace, Graphs) | 🟡 Gradient Mesh, Live Paint, Image Trace (15 presets, the 14 documented ones each with an enhanced version; Ignore Color, Shapes, Auto Grouping and Gradients options; measured in `image-trace-quality.md`; the Flat Logo mode places edges to a fraction of a pixel, restores sharp corners, snaps lines and circles, and refuses gradients), Recolor Artwork, colour management (ICC, soft proofing, separations preview), Graphs (all 9 tools, Graph Data/Type, group-selected series colours persist through regenerate/save/open) done; Graph Design and Marker designs, Transpose and Switch x/y, `|` label line breaks, the pie options, drop shadows, the legend across the top, overlapping widths, First Row/Column in Front, filled lines, kept label formatting and the Graph Data worksheet done; graph Column designs pending | 6–10 |
 | M13 | Automation (Actions ✅ record/playback, persisted; variables, scripting, batch) | 🟡 MCP `add_text` exposes existing vertical point, area and path type; broader scripting and batch work remains | 18–27 |
-| M12 | Advanced color & art (CMYK/ICC, separations, Gradient Mesh, Live Paint, Image Trace, Graphs) | 🟡 Gradient Mesh, Live Paint, Image Trace (junction-returning pieces retain their positioned boundaries; a simpler contour walk with identical output; an edge's sub-pixel shift is the same from either side; notches read only their own piece; quick presets reveal adjustment controls; Properties reopens them; tiny fitted contours retain islands and holes; 15 presets, the 14 documented ones each with an enhanced version; Ignore Color, Shapes, Auto Grouping and Gradients options; measured in `image-trace-quality.md`; closed outlines retain their interior after straightening; the Flat Logo mode places edges to a fraction of a pixel, restores sharp corners, snaps lines and circles, and refuses gradients), Recolor Artwork, colour management (ICC, soft proofing, separations preview), Graphs (all 9 tools, Graph Data/Type, group-selected series colours persist through regenerate/save/open) done; Graph Design and Marker designs, Transpose and Switch x/y, `|` label line breaks, the pie options, drop shadows, the legend across the top, overlapping widths, First Row/Column in Front, filled lines, kept label formatting and the Graph Data worksheet done; graph Column designs pending | 6–10 |
+| M12 | Advanced color & art (CMYK/ICC, separations, Gradient Mesh, Live Paint, Image Trace, Graphs) | 🟡 Gradient Mesh, Live Paint, Image Trace (junction-returning pieces retain their positioned boundaries; a simpler contour walk with identical output; an edge's sub-pixel shift is the same from either side; notches read only their own piece; collapsed loops keep few segments; quick presets reveal adjustment controls; Properties reopens them; tiny fitted contours retain islands and holes; 15 presets, the 14 documented ones each with an enhanced version; Ignore Color, Shapes, Auto Grouping and Gradients options; measured in `image-trace-quality.md`; closed outlines retain their interior after straightening; the Flat Logo mode places edges to a fraction of a pixel, restores sharp corners, snaps lines and circles, and refuses gradients), Recolor Artwork, colour management (ICC, soft proofing, separations preview), Graphs (all 9 tools, Graph Data/Type, group-selected series colours persist through regenerate/save/open) done; Graph Design and Marker designs, Transpose and Switch x/y, `|` label line breaks, the pie options, drop shadows, the legend across the top, overlapping widths, First Row/Column in Front, filled lines, kept label formatting and the Graph Data worksheet done; graph Column designs pending | 6–10 |
 | M12 | Advanced color & art (CMYK/ICC, separations, Gradient Mesh, Live Paint, Image Trace, Graphs) | 🟡 Gradient Mesh, Live Paint, Image Trace (junction-returning pieces retain their positioned boundaries; quick presets trace at once and the Image Trace button opens the adjustment controls; tiny fitted contours retain islands and holes; 15 presets, the 14 documented ones each with an enhanced version; Ignore Color, Shapes, Auto Grouping and Gradients options; measured in `image-trace-quality.md`; closed outlines retain their interior after straightening; the Flat Logo mode places edges to a fraction of a pixel, restores sharp corners, snaps lines and circles, and refuses gradients), Recolor Artwork, colour management (ICC, soft proofing, separations preview), Graphs (all 9 tools, Graph Data/Type, group-selected series colours persist through regenerate/save/open) done; Graph Design and Marker designs, Transpose and Switch x/y, `|` label line breaks, the pie options, drop shadows, the legend across the top, overlapping widths, First Row/Column in Front, filled lines, kept label formatting and the Graph Data worksheet done; graph Column designs pending | 6–10 |
 | M13 | Automation (Actions ✅ record/playback, persisted; variables, scripting, batch) | 🟡 | 18–27 |
 | M14 | 1.0 polish (preferences, shortcut editor, workspaces, accessibility, packaging for all OSes) | 🟡 Numeric-field pointer selection and focus regression-tested (#1326, in part; short movements still select all); RPM runtime capabilities and glibc floor checked (#1275; real-distro install/start-up pending), Eyedropper cursor with precise-setting checks (#1269), Preferences, shortcut editor (chords with Shift and a punctuation key fire as typed; other apps' text shortcut sets imported), workspaces, a custom title bar on Windows/Linux with a Home button, content-sized dialogs, menus that scroll when longer than the window and macOS native menu dismissal done (M14.8), and native macOS save sheets with a Format menu (#866); an experimental, unsupported Windows 7 x64 portable OpenGL build (not verified by maintainers); accessibility and broader Windows/Linux packaging/QA pending | 18–28 |
@@ -87,6 +87,7 @@ M3 follow-up (#1968): native saves retain the per-document transparency grid set
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-16 | minor | Image Trace: a loop or junction-returning piece whose fit collapsed to one cubic keeps the fewest segments that hold its area and course instead of every positioned point, so a higher Paths no longer gives fewer segments on code-drawn noisy images (six falling runs to none; one fall with another cause remains). Scores and hours unchanged. |
 | 2026-10-16 | minor | Image Trace: a notch corner is cut only when the straight edges beside it lie in the shared piece, so both regions of the piece get the same points (code-drawn noisy colour images: 93 uncovered sample points to 0). Scores and hours unchanged. |
 | 2026-10-16 | minor | Image Trace: a crack's sub-pixel shift is the mean of the readings from its two sides, exactly antisymmetric, so abutting regions get the same points on thin slivers (a code-drawn noisy ripple went from 482–1,228 uncovered sample points per trace to 0). Scores and hours unchanged. |
 | 2026-10-16 | minor | Image Trace: the contour walk works out each turn from the pixels as it goes instead of following a precomputed table of per-corner directions; identical loops on all 65,536 4 × 4 masks and 400 seeded masks, and no slower (whole 1 MP traces 1–5% faster). Scores and hours unchanged. |

docs/target-app-parity.md

@@ -1,6 +1,6 @@
 # Parity with Adobe Illustrator
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-17 · **Change:** minor (Image Trace: the notch rule reads only its own piece; Image Trace: an edge's sub-pixel shift is the same from either side; Image Trace Flat Logo traces line art on white paper instead of a blank result; score and hours unchanged; Image Trace: a simpler contour walk with no precomputed direction table; transparency grid visibility saved in native documents, #1968; MCP cancellation, progress and busy answers during long exports, #2165, #2171, #2172; EPS editing data: legacy mesh corners, vector opacity masks and compound member paint retained; raster page comparison filters minification without relaxing limits; scores and hours unchanged; native family-name fallback from English-only typographic names, #2208; scores unchanged; batch exporting, #1935; G2: Effect › Sketch › Halftone Pattern; Photoshop filters 30/57, 27 remaining (22–38 h); G5: Symbol Options Export Type (Graphic / Movie Clip); Localization: Brazilian Portuguese complete under the tests, #1914, 71% → 74%; G6 image variables: Automation ~60% → ~62% / detail ~65% → ~68%, hours lowered; Warp Options controls verified by focused checks and original-image review; estimates unchanged; G11: Asset Export Art Optimized seam (#983 / #1037) and supersampled thumbs; Export for Screens 85% → 90%; existing-guide Escape cancellation validated 2026-10-14; scores and hours unchanged; open-path anchor Delete keeps surviving runs separate; estimates unchanged; PDF.R1: shared PDF reader with windowed content scanning and explicit incomplete-content errors; scores and estimates unchanged; PDF.W1: guarded shared PDF writer; output behavior, scores and estimates unchanged; Artboard tab-switch follow-up historically validated on `a0671777`; scores and hours unchanged; Artboard clean active-tab close/Delete follow-up validated 2026-10-15; later 2026-10-14 merges: anchor X/Y/W/H, #1824; Snap to Grid over Snap to Pixel, #1816; toolbar and All Tools, #1751; Actions panel selection, #1629 in part; redo during a drag, #1719; preferences written on OK, #1747; type in symbols after reopening, #1738; macOS save sheets, #1855, the Format menu withdrawn; stroke outlines shared, #1667; untrusted files, #1852, #1862–#1873; failed-save dialog, #1685; effects, #1864, Dim Images, #1683; duplicated rows of the 2026-10-05 table noted for the owner; scores unchanged; Image Trace: Shapes rework, stroke caps, enhanced presets, gradients over noise, measured in `image-trace-quality.md`, score unchanged; verified PngSuite downloads, #1729; synthetic control-input budgets, #1709; 2026-10-14 merges: anchor Align and Distribute, #1636; Direct Selection and Delete fixes, #1674, #1666, #1743; Escape while typing, #1686; Pen clicks, #1663; Expand on repeats, #1756; Roughen and Scribble, #1643, #1648; file and input hardening, #1776–#1783, #1786, #1807; MCP limits and envelope, #1727, #1728; Image Trace levelling and Flat Logo on scans, #1647, #1657; scores unchanged; later 2026-10-13 merges: SVG import, #1565, #1596, #1568, #1598, #1601; type on a path from PDF and `.ai`, #1585, #1586; ICC tag alignment, #1584; saves, #1620 in part; Warp Arc, #1578; Zig Zag, #1558; Pathfinder strokes, #1570; OpenType features, #1607; intersect Smart Guides, #1602 in part; a guide's position in the Transform panel, #1597 in part, a convenience with no parity claim; scores unchanged; TIFF is available in Export for Screens and Asset Export with shared format settings; scores and hours unchanged; G1/M11: Artboard deletion and history selection normalization; history regressions and full workspace CI pass; scores and hours unchanged; Character styles retain explicit Auto leading, propagate resets and preserve local leading overrides; scores and hours unchanged; Width Point Edit: Shift-double-click enables adjoining adjustment; plain double-click keeps it off; scores and hours unchanged; Units › Identify Objects By (`identifyObjectsBy`) acts on Layers, Variables and Layer Options, #394, scores unchanged; Appearance of Black › Printing / Exporting (`blackOutput`) acts on RGB raster export and Print as Bitmap, #394, scores unchanged; per-corner radius fields with a link toggle, split from #1594; control transport deadlines, #1726; Color panel: the mode picked last comes back after a restart, #1675; Image Trace: shared edges, memory, thin lines, strokes, corners, and the Shapes, Auto Grouping and Gradients options, measured in `image-trace-quality.md`, score unchanged; 2026-10-13 merges: Polish interface, #1498; compact native saves, #1492; PDF and EPS paste as vector art, #1499; import fixes for `.ai`, PDF, EPS and SVG, #1528, #1530, #1531, #1544, #1551, #1553; guide objects, #1534; Join after Average, #1533; Keyboard Shortcuts lists commands outside the menus, #1539; correction: Average and Join with a corner or smooth choice is missing; scores unchanged; late 2026-10-12 merges: type that does not fit its frame iLine truncated
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-17 · **Change:** minor (Image Trace: a higher Paths never gives fewer segments on collapsed loops; Image Trace: the notch rule reads only its own piece; Image Trace: an edge's sub-pixel shift is the same from either side; Image Trace Flat Logo traces line art on white paper instead of a blank result; score and hours unchanged; Image Trace: a simpler contour walk with no precomputed direction table; transparency grid visibility saved in native documents, #1968; MCP cancellation, progress and busy answers during long exports, #2165, #2171, #2172; EPS editing data: legacy mesh corners, vector opacity masks and compound member paint retained; raster page comparison filters minification without relaxing limits; scores and hours unchanged; native family-name fallback from English-only typographic names, #2208; scores unchanged; batch exporting, #1935; G2: Effect › Sketch › Halftone Pattern; Photoshop filters 30/57, 27 remaining (22–38 h); G5: Symbol Options Export Type (Graphic / Movie Clip); Localization: Brazilian Portuguese complete under the tests, #1914, 71% → 74%; G6 image variables: Automation ~60% → ~62% / detail ~65% → ~68%, hours lowered; Warp Options controls verified by focused checks and original-image review; estimates unchanged; G11: Asset Export Art Optimized seam (#983 / #1037) and supersampled thumbs; Export for Screens 85% → 90%; existing-guide Escape cancellation validated 2026-10-14; scores and hours unchanged; open-path anchor Delete keeps surviving runs separate; estimates unchanged; PDF.R1: shared PDF reader with windowed content scanning and explicit incomplete-content errors; scores and estimates unchanged; PDF.W1: guarded shared PDF writer; output behavior, scores and estimates unchanged; Artboard tab-switch follow-up historically validated on `a0671777`; scores and hours unchanged; Artboard clean active-tab close/Delete follow-up validated 2026-10-15; later 2026-10-14 merges: anchor X/Y/W/H, #1824; Snap to Grid over Snap to Pixel, #1816; toolbar and All Tools, #1751; Actions panel selection, #1629 in part; redo during a drag, #1719; preferences written on OK, #1747; type in symbols after reopening, #1738; macOS save sheets, #1855, the Format menu withdrawn; stroke outlines shared, #1667; untrusted files, #1852, #1862–#1873; failed-save dialog, #1685; effects, #1864, Dim Images, #1683; duplicated rows of the 2026-10-05 table noted for the owner; scores unchanged; Image Trace: Shapes rework, stroke caps, enhanced presets, gradients over noise, measured in `image-trace-quality.md`, score unchanged; verified PngSuite downloads, #1729; synthetic control-input budgets, #1709; 2026-10-14 merges: anchor Align and Distribute, #1636; Direct Selection and Delete fixes, #1674, #1666, #1743; Escape while typing, #1686; Pen clicks, #1663; Expand on repeats, #1756; Roughen and Scribble, #1643, #1648; file and input hardening, #1776–#1783, #1786, #1807; MCP limits and envelope, #1727, #1728; Image Trace levelling and Flat Logo on scans, #1647, #1657; scores unchanged; later 2026-10-13 merges: SVG import, #1565, #1596, #1568, #1598, #1601; type on a path from PDF and `.ai`, #1585, #1586; ICC tag alignment, #1584; saves, #1620 in part; Warp Arc, #1578; Zig Zag, #1558; Pathfinder strokes, #1570; OpenType features, #1607; intersect Smart Guides, #1602 in part; a guide's position in the Transform panel, #1597 in part, a convenience with no parity claim; scores unchanged; TIFF is available in Export for Screens and Asset Export with shared format settings; scores and hours unchanged; G1/M11: Artboard deletion and history selection normalization; history regressions and full workspace CI pass; scores and hours unchanged; Character styles retain explicit Auto leading, propagate resets and preserve local leading overrides; scores and hours unchanged; Width Point Edit: Shift-double-click enables adjoining adjustment; plain double-click keeps it off; scores and hours unchanged; Units › Identify Objects By (`identifyObjectsBy`) acts on Layers, Variables and Layer Options, #394, scores unchanged; Appearance of Black › Printing / Exporting (`blackOutput`) acts on RGB raster export and Print as Bitmap, #394, scores unchanged; per-corner radius fields with a link toggle, split from #1594; control transport deadlines, #1726; Color panel: the mode picked last comes back after a restart, #1675; Image Trace: shared edges, memory, thin lines, strokes, corners, and the Shapes, Auto Grouping and Gradients options, measured in `image-trace-quality.md`, score unchanged; 2026-10-13 merges: Polish interface, #1498; compact native saves, #1492; PDF and EPS paste as vector art, #1499; import fixes for `.ai`, PDF, EPS and SVG, #1528, #1530, #1531, #1544, #1551, #1553; guide objects, #1534; Join after Average, #1533; Keyboard Shortcuts lists commands outside the menus, #1539; correction: Average and Join with a corner or smooth choice is missing; sLine truncated
 
 The authoritative parity assessment. [`ROADMAP.md`](../ROADMAP.md) summarizes it; [`gaps.md`](gaps.md) is
 the work list made from it. Deep areas have their own checklists: [UI and interaction](ui-parity.md),
@@ -80,7 +80,7 @@ dominate; 3D, graphs and automation are specialist). They sum to 105. Feature de
 | Type core | 9 | 80% | Auto-leading style resets are implemented; remaining:  hyphenation and justification options, Optical Margin Alignment, Middle Eastern features beyond bidi layout, optional group font-size preservation; transformed character controls fixed (#1034), see [type-parity.md](type-parity.md) | 14–19 | estimated; full-name font matches regression-tested (#1258); mixed paragraph alignment indication implemented; headless regressions, full integration CI and visual review pass; localized legacy family-name fallback with loaded/catalog regressions (#2208) |
 | Type advanced (CJK, spelling, Touch Type, Retype) | 4 | 50% | CJK vertical composition (ruby, mojikumi), variable font axes, tab leaders, spell check, Touch Type, Retype | 20–28 | estimated; upright fallback for fullwidth `！` / `？` regression-tested; score and hours unchanged |
 | Symbols, blends, envelopes, Repeat, perspective | 5 | 87% | 30.7's Blend panel with ease in/out, dynamic symbols, symbol libraries, Start Global Edit, envelope Anti-Alias/Preserve Shape; Symbol Options › Registration and Export Type (Graphic / Movie Clip) are done | 5–9 | estimated |
-| Image Trace, graphs, image tools | 3 | 75% | graph Column designs, Image Trace Create Strokes depth (Create Object Mosaic is done; junction-returning piece survival has source-generated regressions in `image-trace-quality.md`; simpler contour walk, identical output; an edge's sub-pixel shift is the same from either side; notches read only their own piece) | 5–8 | estimated (raised from 72%); quick presets reveal adjustment controls, Properties reopens them |
+| Image Trace, graphs, image tools | 3 | 75% | graph Column designs, Image Trace Create Strokes depth (Create Object Mosaic is done; junction-returning piece survival has source-generated regressions in `image-trace-quality.md`; simpler contour walk, identical output; an edge's sub-pixel shift is the same from either side; notches read only their own piece; collapsed loops keep few segments, so Paths is monotone on the code-drawn sweep) | 5–8 | estimated (raised from 72%); quick presets reveal adjustment controls, Properties reopens them |
 | Layers, artboards, document setup | 5 | 78% | Selected-artboard deletion is consistent across panel actions (all-selected retains artboard 1); history prunes removed indices while preserving valid multiselection; remaining:  30.0's artboard locking and colours and managing artboards from the canvas, Layers panel row context menus and Collect for Export (click-to-fit objects is done, #1227) | 5–8 | estimated (lowered from 82%: target moved); Artboard deletion keys keep artwork and the first of an all-selected set |
 | View & navigation | 3 | 70% | New View/Edit Views, multiple windows and Arrange, Snap to Glyph | 9–14 | estimated |
 | File formats | 6 | 75% | `.ai` files open with a flattened or wrong layer structure in real cases (#951), guides lost (#779), no writing of Illustrator's editing data (#868), FreeHand/CorelDRAW/DWG/HEIC/JPEG 2000 import, 3D export; see [file-format-parity.md](file-format-parity.md); EPS legacy mesh/opacity-mask and raster comparison follow-up verified | 10–20 | estimated (lowered from 85%: open issues); DXF control-point SPLINE import closure regression-tested (#1299 follow-up after #1320); PDF writer metadata, reader streaming and immutable backend checks in `crates/pdf/src/tests.rs`, `crates/pdf/src/tests_reader_streaming.rs` and `xtask/src/pdf_deps.rs` |
@@ -579,6 +579,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
   Disable, Enable, Unlink and Link Opacity Mask and Opacity Mask Options (`transparency.setOpacityMask`) record no undo step when every mask they act on already has the flags they set.
 - **Image Trace, thin closed outlines:** generated `fit::snap_area_tests` verify nonzero interiors after straightening, opposite closed-boundary winding and Noise controls; see [quality notes](image-trace-quality.md#thin-closed-outlines-with-snap-curves-to-lines). Scores and hours unchanged; open-piece fitting is unchanged.
 - **Image Trace small contours:** closed fits too small to form an editable subpath retain their positioned outline, including holes. Source-generated island, hole/winding and stepped-region regressions cover Corners and Noise; defaults, parity scores and estimates are unchanged.
+- **Image Trace, collapsed loops keep few segments:** a loop whose fit collapses to one cubic keeps the fewest segments that hold its area and course, so a higher Paths gives no fewer segments; a code-drawn Paths sweep in `crates/trace` (see [quality notes](image-trace-quality.md#collapsed-loops-keep-few-segments)).
 - **Image Trace, notches read only their own piece:** the notch rule of `subpixel::outline` reads only the shared piece, so both regions of an edge cut a corner pixel alike and leave no gap; a code-drawn noisy multi-colour coverage test in `crates/trace` (see [quality notes](image-trace-quality.md#notches-read-only-their-own-piece)).
 - **Image Trace, same shift from either side of an edge:** a crack's sub-pixel shift is averaged from its two sides, so abutting regions on one- and two-pixel slivers get the same points and leave nothing uncovered; code-drawn regressions in `crates/trace` (see [quality notes](image-trace-quality.md#same-sub-pixel-shift-from-either-side-of-an-edge)).
 - **Image Trace, simpler contour walk:** `contour::trace_mask` works out each turn from the pixels during the walk, with no precomputed direction table and no assertion; identical loops to the previous walk on every 4 × 4 mask (see [quality notes](image-trace-quality.md#a-simpler-contour-walk)).
@@ -714,6 +715,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-16 | minor | Image Trace: a loop or junction-returning piece whose fit collapsed to one cubic keeps the fewest segments that hold its area and course instead of every positioned point, so a higher Paths no longer gives fewer segments on code-drawn noisy images (six falling runs to none; one fall with another cause remains). Scores and hours unchanged. |
 | 2026-10-16 | minor | Image Trace: a notch corner is cut only when the straight edges beside it lie in the shared piece, so both regions of the piece get the same points (code-drawn noisy colour images: 93 uncovered sample points to 0). Scores and hours unchanged. |
 | 2026-10-16 | minor | Image Trace: a crack's sub-pixel shift is the mean of the readings from its two sides, exactly antisymmetric, so abutting regions get the same points on thin slivers (a code-drawn noisy ripple went from 482–1,228 uncovered sample points per trace to 0). Scores and hours unchanged. |
 | 2026-10-16 | minor | Image Trace Flat Logo: line art whose only solid area is the paper (thin strokes, small marks) is traced from its strokes' cores instead of returning a blank success with no paths; anti-aliased edge shades fold into their ink, and paper with ink on under 1% of it (specks, grain) stays blank; code-drawn regressions `thin_line_art_on_paper_is_traced_not_blank`, `anti_aliased_coloured_lettering_has_only_its_inks`, `sparse_marks_on_paper_are_not_promoted_to_colours`, `grainy_blank_paper_has_no_ink`. Score and hours unchanged (estimated) |