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bflatastic 20ec49b2e7 Image Trace: abutting regions share one curve along their edge

Each region's outline was fitted on its own, so the edge between two regions was fitted twice, a little
differently, and left hairline gaps and overlaps.

- An outline is cut at its junctions: the pixel corners where three or more regions meet, where two parts of a
  region touch by a corner only, and where an edge reaches the image's border (each side of the image is a
  neighbour of its own, so the image's corners stay exact). A junction lies where the edges around it say, the
  same for every region around it.
- Each piece between two junctions is the whole edge between two regions. Both get exactly the same points for
  it (shifts are rounded to 1/1024 px so that the two sides agree to the last bit; whether a piece is hard is
  decided by the piece alone) and it is fitted the same way from either side (from its end further left), so it
  is one and the same curve in both paths. A loop without junctions is fitted clockwise from its leftmost point:
  a shape's outline and the hole it leaves in the shape around it are one curve too.
- Stacked layers (Overlapping) share no edges and are cut at the image's border only.

On each preset's own inputs, all sizes and variants (docs/image-trace-quality.md), before -> after:
- Default: gaps 22.2 -> 0.8 px, overlaps 22.4 -> 0.5 px
- 3 Colors: gaps 48.6 -> 0.0, overlaps 29.4 -> 0.0; outlines 0.087 -> 0.104 px off on average
- 6 Colors: gaps 39.0 -> 0.2, overlaps 35.7 -> 0.3; 0.137 -> 0.140 px off, largest 1.09 -> 1.34
- 16 Colors: gaps 34.5 -> 0.2, overlaps 26.4 -> 0.2; 0.133 -> 0.141 px off, largest 1.09 -> 1.31

2026-10-13 06:00:40 +07:00

38 KiB

Raw Blame History

Image Trace quality

Last reviewed: 2026-10-13 · Last updated: 2026-10-13 · Change: minor (shared edges: gaps and overlaps between abutting paths from 22 to 50 px down to under 1)

What Image Trace (crates/trace) makes of images whose right answer is known, measured by a harness and compared with the numbers before each change. Nothing here is a judgement by eye, and nothing is compared with any other product except the open tracer named under Yardstick.

How it is measured

crates/trace/tests/quality draws its own inputs from vector art (no image files), traces each with every built-in preset, and measures the result:

TRACE_QUALITY_REPORT=report.md cargo test --release -p vectorcraft-trace --test quality -- --ignored

Inputs (drawn anti-aliased at 128, 256 and 512 px, and at 256 px also blurred, with compression-like noise, as a scan of ink on cream paper with uneven light and grain, and aliased: one hard sample per pixel, no anti-aliasing):

kind	inputs
curved shapes	a circle; two ellipses; a rounded badge with a round hole; a letter D with its counter
polygons	a triangle, a turned square and a hexagon; a five-pointed star; a letter A with its counter
thin lines	five lines 0.5, 1, 2, 3 and 5 units wide (of a 256-unit square), a few degrees off the pixel grid
flat colour art	a disc of two halves in different colours that touch; a badge of four colours on white
gradient, photo	a smooth two-way gradient with a glow; a photo-like image (soft-edged shaded objects, texture, sensor noise)

The letters are drawn by hand from lines and curves: the repository has no font to set them in.

Columns

column	meaning
ΔE	the trace drawn again against the source: mean colour difference in Oklab × 100 (black to white is 100)
edge ΔE	the same, weighted by how strong an edge the source has at each pixel
off mean, off max	distance (px) from the traced outlines to the art's true outlines: wobble and staircase
missed max	largest distance (px) from a true outline to the nearest traced one: what was lost
paths, anchors	counts, the background's frame aside
× art	anchors per anchor point of the art itself (1.00 is as economical as the original)
lines %	share of the outline length made of straight segments (100 is right for polygons, 0 for a circle)
corners %	share of the art's sharp corners with a traced corner within 1.5 px
kinks	anchors where the outline turns by 10° or more away from any true corner
odd colours, odd px	paths (and their area) in a colour the art doesn't have: slivers along anti-aliased edges
gap px, overlap px	area no path covers, and area covered twice (abutting traces with a white background only)
specks	paths under 6 px of area
outside px	how far the trace reaches outside the image: a curve that strays

Black-and-white presets trace black: on the scanned variant their ΔE includes the paper's and ink's own colours. – means the measure does not apply; all that nothing was traced.

Baseline and now

Each preset on the inputs it is meant for, all sizes and variants.

Baseline (before any change, main at `baf9693f`)

preset	inputs	ΔE	edge ΔE	off mean	off max	missed max	paths	anchors	× art	lines %	corners %	kinks	odd colours	odd px	gap px	overlap px	specks	outside px
Default	circle, ellipses, badge with a hole, letter D, polygons, star, letter A	2.79	17.15	0.313	1.51	2.52	1.9	14	1.45	34	76	1.4	–	–	63.5	67.0	0.0	0.0
High Fidelity Photo	gradient, photo-like	2.30	2.63	–	–	–	3652.6	46866	–	84	–	–	–	–	0.0	–	1169.4	0.3
Low Fidelity Photo	gradient, photo-like	2.61	2.94	–	–	–	128.3	3867	–	42	–	–	–	–	0.0	–	0.0	0.7
3 Colors	two touching halves	4.93	11.38	0.482	2.35	89.09	2.1	14	2.31	12	29	2.1	1.6	15418	118.0	87.3	0.0	0.0
6 Colors	two touching halves, four-colour badge	0.78	8.82	4.383	83.10	30.11	21.2	270	30.18	51	98	213.8	2.4	272	198.8	194.6	0.0	0.3
16 Colors	two touching halves, four-colour badge	0.74	9.02	5.115	86.21	4.32	69.9	923	102.80	58	100	765.9	5.9	670	293.7	329.9	0.0	0.5
Shades of Gray	gradient, photo-like	9.29	9.16	–	–	–	90.8	1921	–	42	–	–	–	–	0.0	–	0.2	0.5
Black and White Logo	circle, ellipses, badge with a hole, letter D, polygons, star, letter A	2.76	15.96	0.270	1.76	2.53	1.4	31	3.78	90	81	15.3	–	–	–	–	0.0	0.0
Sketched Art	circle, ellipses, badge with a hole, letter D, lines	2.85	17.04	0.302	1.63	105.63	1.8	14	1.34	28	18	1.4	–	–	–	–	0.0	0.0
Silhouettes	circle, ellipses, badge with a hole, letter D	3.04	21.41	0.573	2.88	2.89	1.2	10	1.16	9	86	1.4	–	–	–	–	0.0	0.0
Line Art	lines	2.77	12.51	0.158	1.13	105.76	5.4	25	1.27	90	–	–	–	–	–	–	0.0	0.0
Technical Drawing	polygons, star, letter A, lines	2.66	13.45	0.201	1.37	105.76	4.8	32	2.23	100	85	5.9	–	–	–	–	0.1	0.0
Flat Logo	two touching halves, four-colour badge	0.43	3.53	3.106	88.50	0.78	69.9	352	38.92	38	80	237.0	0.0	0	13.8	–	59.1	0.2

Now (sub-pixel edges, the palette, photo smoothing, shared edges)

preset	inputs	ΔE	edge ΔE	off mean	off max	missed max	paths	anchors	× art	lines %	corners %	kinks	odd colours	odd px	gap px	overlap px	specks	outside px
Default	circle, ellipses, badge with a hole, letter D, polygons, star, letter A	2.60	10.04	0.092	1.02	2.17	1.9	18	1.78	29	68	0.4	–	–	0.8	0.5	0.0	0.0
High Fidelity Photo	gradient, photo-like	1.75	1.97	–	–	–	120.7	10001	–	38	–	–	–	–	0.0	–	10.3	0.0
Low Fidelity Photo	gradient, photo-like	2.45	2.69	–	–	–	37.1	2118	–	41	–	–	–	–	0.0	–	0.0	0.0
3 Colors	two touching halves	0.42	3.98	0.104	0.91	0.91	2.0	11	1.81	39	100	0.0	0.0	0	0.0	0.0	0.0	0.0
6 Colors	two touching halves, four-colour badge	0.55	4.98	0.140	1.34	1.19	4.0	50	3.13	38	86	5.2	0.0	0	0.2	0.3	0.0	0.0
16 Colors	two touching halves, four-colour badge	0.55	4.90	0.141	1.31	1.19	4.2	62	3.79	39	86	6.4	0.0	0	0.2	0.2	0.0	0.0
Shades of Gray	gradient, photo-like	9.26	9.06	–	–	–	16.5	695	–	51	–	–	–	–	0.0	–	0.5	0.0
Black and White Logo	circle, ellipses, badge with a hole, letter D, polygons, star, letter A	2.58	9.37	0.063	1.02	2.17	1.4	27	2.69	39	68	0.2	–	–	–	–	0.0	0.0
Sketched Art	circle, ellipses, badge with a hole, letter D, lines	2.71	12.12	0.197	1.00	105.53	1.8	17	1.48	15	86	0.0	–	–	–	–	0.0	0.0
Silhouettes	circle, ellipses, badge with a hole, letter D	2.98	19.22	0.523	2.23	2.21	1.2	14	1.64	11	75	0.2	–	–	–	–	0.0	0.0
Line Art	lines	2.65	9.88	0.093	0.91	105.75	5.4	78	3.92	36	–	–	–	–	–	–	0.1	0.0
Technical Drawing	polygons, star, letter A, lines	2.55	9.72	0.092	1.06	105.75	4.8	56	3.67	71	74	0.7	–	–	–	–	1.3	0.0
Flat Logo	two touching halves, four-colour badge	0.43	3.53	3.106	88.50	0.78	69.9	352	38.92	38	80	237.0	0.0	0	13.8	–	59.1	0.2

The sections below are the numbers now (sub-pixel edges, the palette, photo smoothing, shared edges).

1. Each preset on the inputs it is meant for

All sizes and variants (clean, aliased, blurred, noisy, scanned) of those inputs.

preset	inputs	ΔE	edge ΔE	off mean	off max	missed max	paths	anchors	× art	lines %	corners %	kinks	odd colours	odd px	gap px	overlap px	specks	outside px
Default	circle, ellipses, badge with a hole, letter D, polygons, star, letter A	2.60	10.04	0.092	1.02	2.17	1.9	18	1.78	29	68	0.4	–	–	0.8	0.5	0.0	0.0
High Fidelity Photo	gradient, photo-like	1.75	1.97	–	–	–	120.7	10001	–	38	–	–	–	–	0.0	–	10.3	0.0
Low Fidelity Photo	gradient, photo-like	2.45	2.69	–	–	–	37.1	2118	–	41	–	–	–	–	0.0	–	0.0	0.0
3 Colors	two touching halves	0.42	3.98	0.104	0.91	0.91	2.0	11	1.81	39	100	0.0	0.0	0	0.0	0.0	0.0	0.0
6 Colors	two touching halves, four-colour badge	0.55	4.98	0.140	1.34	1.19	4.0	50	3.13	38	86	5.2	0.0	0	0.2	0.3	0.0	0.0
16 Colors	two touching halves, four-colour badge	0.55	4.90	0.141	1.31	1.19	4.2	62	3.79	39	86	6.4	0.0	0	0.2	0.2	0.0	0.0
Shades of Gray	gradient, photo-like	9.26	9.06	–	–	–	16.5	695	–	51	–	–	–	–	0.0	–	0.5	0.0
Black and White Logo	circle, ellipses, badge with a hole, letter D, polygons, star, letter A	2.58	9.37	0.063	1.02	2.17	1.4	27	2.69	39	68	0.2	–	–	–	–	0.0	0.0
Sketched Art	circle, ellipses, badge with a hole, letter D, lines	2.71	12.12	0.197	1.00	105.53	1.8	17	1.48	15	86	0.0	–	–	–	–	0.0	0.0
Silhouettes	circle, ellipses, badge with a hole, letter D	2.98	19.22	0.523	2.23	2.21	1.2	14	1.64	11	75	0.2	–	–	–	–	0.0	0.0
Line Art	lines	2.65	9.88	0.093	0.91	105.75	5.4	78	3.92	36	–	–	–	–	–	–	0.1	0.0
Technical Drawing	polygons, star, letter A, lines	2.55	9.72	0.092	1.06	105.75	4.8	56	3.67	71	74	0.7	–	–	–	–	1.3	0.0
Flat Logo	two touching halves, four-colour badge	0.43	3.53	3.106	88.50	0.78	69.9	352	38.92	38	80	237.0	0.0	0	13.8	–	59.1	0.2

2. Each preset on each kind of input (clean, three sizes)

preset	inputs	ΔE	edge ΔE	off mean	off max	missed max	paths	anchors	× art	lines %	corners %	kinks	odd colours	odd px	gap px	overlap px	specks	outside px
Default	curved shapes	0.09	3.51	0.062	0.64	0.78	1.8	15	1.64	13	83	0.0	–	–	0.0	0.0	0.0	0.0
Default	polygons	0.05	2.13	0.036	0.44	1.24	2.0	14	1.26	89	90	0.0	–	–	0.0	0.0	0.0	0.0
Default	thin lines	0.56	4.77	0.061	0.47	105.57	3.3	24	1.18	43	–	–	–	–	0.0	0.0	0.0	0.0
Default	flat colour art	19.95	19.00	0.199	0.53	179.52	1.5	19	1.18	14	0	0.0	–	–	0.0	0.0	0.0	0.0
Default	gradient, photo	39.14	38.78	–	–	–	3.2	593	–	55	–	–	–	–	18.6	30.6	0.0	0.0
High Fidelity Photo	curved shapes	0.04	1.66	0.026	0.18	0.20	1.2	19	2.12	20	100	0.0	0.0	0	0.0	–	0.0	0.0
High Fidelity Photo	polygons	0.05	1.88	0.031	0.51	1.34	1.7	16	1.43	88	89	0.0	0.0	0	0.0	–	0.0	0.0
High Fidelity Photo	thin lines	0.34	5.96	0.075	0.85	4.31	40.3	339	16.93	37	–	–	27.3	4490	0.0	–	19.0	0.0
High Fidelity Photo	flat colour art	0.14	4.16	0.030	0.20	0.20	3.5	73	4.62	35	100	0.0	0.0	0	0.0	–	0.0	0.0
High Fidelity Photo	gradient, photo	1.80	2.04	–	–	–	134.7	11321	–	39	–	–	–	–	0.0	–	7.3	0.0
Low Fidelity Photo	curved shapes	0.06	2.65	0.047	0.31	0.31	1.2	13	1.47	17	100	0.0	0.0	0	0.0	–	0.0	0.0
Low Fidelity Photo	polygons	0.05	2.15	0.036	0.51	1.34	1.7	14	1.22	88	89	0.0	0.0	0	0.0	–	0.0	0.0
Low Fidelity Photo	thin lines	0.51	5.69	0.083	0.86	45.41	7.0	56	2.80	47	–	–	4.0	3966	0.0	–	0.0	0.0
Low Fidelity Photo	flat colour art	0.15	4.29	0.045	0.28	0.28	3.5	54	3.38	31	100	0.0	0.0	0	0.0	–	0.0	0.0
Low Fidelity Photo	gradient, photo	2.53	2.80	–	–	–	42.7	2282	–	41	–	–	–	–	0.0	–	0.0	0.0
3 Colors	curved shapes	0.06	2.65	0.047	0.31	0.31	1.8	16	1.70	15	100	0.0	0.0	0	0.0	0.0	0.0	0.0
3 Colors	polygons	0.05	2.15	0.036	0.51	1.34	2.0	15	1.32	88	89	0.0	0.0	0	0.0	0.0	0.0	0.0
3 Colors	thin lines	0.45	4.38	0.113	0.90	45.41	5.0	44	2.18	50	–	–	2.0	290	0.0	0.0	0.0	0.0
3 Colors	flat colour art	1.31	3.61	0.125	0.90	60.25	2.5	25	1.86	45	100	0.0	1.0	9914	0.0	0.0	0.0	0.0
3 Colors	gradient, photo	7.49	7.60	–	–	–	5.7	530	–	47	–	–	–	–	6.3	7.4	0.0	0.0
6 Colors	curved shapes	0.06	2.45	0.043	0.27	0.28	1.8	17	1.78	15	100	0.0	0.0	0	0.0	0.0	0.0	0.0
6 Colors	polygons	0.05	2.08	0.035	0.51	1.34	2.0	15	1.33	88	89	0.0	0.0	0	0.0	0.0	0.0	0.0
6 Colors	thin lines	0.50	4.49	0.102	0.86	45.41	4.0	33	1.65	53	–	–	1.7	396	0.0	0.0	0.0	0.0
6 Colors	flat colour art	0.12	2.70	0.057	0.31	0.30	3.0	28	2.00	43	100	0.0	0.0	0	0.0	0.0	0.0	0.0
6 Colors	gradient, photo	5.00	5.28	–	–	–	13.0	832	–	36	–	–	–	–	6.1	8.2	0.0	0.0
16 Colors	curved shapes	0.05	2.21	0.038	0.24	0.25	1.8	17	1.85	16	100	0.0	0.0	0	0.0	0.0	0.0	0.0
16 Colors	polygons	0.05	1.97	0.032	0.51	1.34	2.0	16	1.39	88	89	0.0	0.0	0	0.0	0.0	0.0	0.0
16 Colors	thin lines	0.41	3.77	0.110	0.86	23.65	8.7	50	2.52	52	–	–	5.7	305	0.0	0.0	0.0	0.0
16 Colors	flat colour art	0.12	2.52	0.052	0.31	0.30	3.0	28	2.11	43	100	0.0	0.0	0	0.0	0.0	0.0	0.0
16 Colors	gradient, photo	3.00	3.30	–	–	–	47.2	2132	–	27	–	–	–	–	12.3	18.0	0.0	0.0
Shades of Gray	curved shapes	0.06	2.67	0.047	0.31	0.31	1.2	14	1.49	17	100	0.0	0.0	0	0.0	–	0.0	0.0
Shades of Gray	polygons	0.05	2.08	0.035	0.47	1.25	1.7	14	1.22	88	90	0.0	0.0	0	0.0	–	0.0	0.0
Shades of Gray	thin lines	0.55	6.55	0.083	0.86	45.40	10.3	73	3.67	50	–	–	8.0	4272	0.0	–	0.0	0.0
Shades of Gray	flat colour art	7.33	11.24	0.257	1.43	179.39	4.7	200	18.45	22	50	0.3	3.7	173367	0.0	–	0.0	0.0
Shades of Gray	gradient, photo	9.71	9.55	–	–	–	18.2	748	–	51	–	–	–	–	0.0	–	0.5	0.0
Black and White Logo	curved shapes	0.04	1.51	0.024	0.50	0.59	1.2	21	2.29	20	83	0.0	–	–	–	–	0.0	0.0
Black and White Logo	polygons	0.04	1.83	0.030	0.43	1.24	1.7	16	1.39	90	90	0.0	–	–	–	–	0.0	0.0
Black and White Logo	thin lines	0.60	6.10	0.111	0.50	77.21	10.3	48	2.38	83	–	–	–	–	–	–	3.3	0.0
Black and White Logo	flat colour art	19.94	18.71	0.192	0.32	179.52	1.0	20	1.22	23	0	0.0	–	–	–	–	0.0	0.0
Black and White Logo	gradient, photo	39.11	38.71	–	–	–	9.0	574	–	67	–	–	–	–	–	–	0.0	0.0
Sketched Art	curved shapes	0.14	5.77	0.112	0.47	0.47	1.2	12	1.38	16	100	0.0	–	–	–	–	0.0	0.0
Sketched Art	polygons	0.12	4.81	0.088	0.52	1.05	1.7	13	1.18	85	88	0.0	–	–	–	–	0.0	0.0
Sketched Art	thin lines	0.40	5.10	0.106	0.80	52.93	4.3	39	1.93	35	–	–	–	–	–	–	0.0	0.0
Sketched Art	flat colour art	20.32	21.13	0.179	0.87	179.64	1.5	24	1.43	16	0	0.0	–	–	–	–	0.0	0.0
Sketched Art	gradient, photo	45.54	45.39	–	–	–	1.0	237	–	43	–	–	–	–	–	–	0.0	0.0
Silhouettes	curved shapes	0.36	14.54	0.282	0.71	0.71	1.2	12	1.34	15	100	0.0	–	–	–	–	0.0	0.0
Silhouettes	polygons	0.35	13.93	0.261	0.67	0.69	1.7	14	1.26	76	85	0.0	–	–	–	–	0.0	0.0
Silhouettes	thin lines	1.03	15.78	0.304	1.09	18.10	5.0	47	2.33	34	–	–	–	–	–	–	0.0	0.0
Silhouettes	flat colour art	23.86	33.99	0.224	0.77	188.38	1.0	11	0.78	24	0	0.0	–	–	–	–	0.0	0.0
Silhouettes	gradient, photo	61.57	61.34	–	–	–	0.2	2	–	42	–	–	–	–	–	–	0.0	0.0
Line Art	curved shapes	0.04	1.86	0.032	0.54	0.62	1.2	16	1.75	19	83	0.0	–	–	–	–	0.0	0.0
Line Art	polygons	0.05	1.90	0.031	0.40	1.24	1.7	14	1.26	90	90	0.0	–	–	–	–	0.0	0.0
Line Art	thin lines	0.54	4.39	0.049	0.47	105.75	3.3	35	1.77	41	–	–	–	–	–	–	0.0	0.0
Line Art	flat colour art	19.94	18.73	0.193	0.50	179.52	1.0	43	2.40	22	0	0.0	–	–	–	–	0.0	0.0
Line Art	gradient, photo	39.12	38.72	–	–	–	7.7	448	–	57	–	–	–	–	–	–	0.0	0.0
Technical Drawing	curved shapes	0.04	1.51	0.024	0.50	0.59	1.2	21	2.29	20	83	0.0	–	–	–	–	0.0	0.0
Technical Drawing	polygons	0.04	1.83	0.030	0.43	1.24	1.7	16	1.38	91	91	0.0	–	–	–	–	0.0	0.0
Technical Drawing	thin lines	0.53	5.83	0.125	0.50	55.75	15.3	61	3.03	88	–	–	–	–	–	–	8.3	0.0
Technical Drawing	flat colour art	19.94	18.71	0.192	0.32	179.52	1.0	20	1.22	23	0	0.0	–	–	–	–	0.0	0.0
Technical Drawing	gradient, photo	39.08	38.68	–	–	–	20.0	593	–	68	–	–	–	–	–	–	2.7	0.0
Flat Logo	curved shapes	0.06	2.14	0.036	0.25	0.25	1.8	31	3.38	19	100	0.0	0.0	0	6.8	–	0.0	0.0
Flat Logo	polygons	0.09	3.44	0.060	0.35	1.03	2.0	35	3.17	67	94	0.0	0.0	0	6.8	–	0.0	0.0
Flat Logo	thin lines	1.17	11.78	0.050	0.49	all	3.0	189	9.45	28	–	–	0.0	0	5467.1	–	0.0	0.0
Flat Logo	flat colour art	0.07	1.53	0.065	0.31	0.27	3.0	36	3.51	47	100	0.0	0.0	0	6.8	–	0.0	0.0
Flat Logo	gradient, photo	refused

3. Each preset on its inputs, by variant (256 px)

preset	variant	ΔE	edge ΔE	off mean	off max	missed max	paths	anchors	× art	lines %	corners %	kinks	odd colours	odd px	gap px	overlap px	specks	outside px
Default	clean	0.07	2.92	0.051	0.64	1.24	1.9	15	1.48	46	89	0.0	–	–	0.0	0.0	0.0	0.0
Default	aliased	0.37	20.23	0.233	1.02	1.35	1.9	15	1.45	21	96	0.0	–	–	0.0	0.0	0.0	0.0
Default	blurred	0.82	16.64	0.078	0.97	2.17	1.9	25	2.42	5	21	1.4	–	–	0.0	0.0	0.0	0.0
Default	noisy	1.74	4.50	0.050	0.54	1.24	1.9	16	1.64	39	67	0.0	–	–	2.3	0.6	0.0	0.0
Default	scanned	15.06	20.19	0.132	0.86	2.17	1.9	25	2.50	0	25	1.1	–	–	3.6	2.9	0.0	0.0
High Fidelity Photo	clean	1.80	2.04	–	–	–	134.7	11321	–	39	–	–	–	–	0.0	–	7.3	0.0
High Fidelity Photo	aliased	1.77	2.00	–	–	–	73.0	8004	–	40	–	–	–	–	0.0	–	5.5	0.0
High Fidelity Photo	blurred	1.59	1.95	–	–	–	72.0	7388	–	40	–	–	–	–	0.0	–	0.5	0.0
High Fidelity Photo	noisy	2.02	2.18	–	–	–	155.5	10856	–	33	–	–	–	–	0.0	–	18.5	0.0
High Fidelity Photo	scanned	1.45	1.55	–	–	–	140.5	9795	–	36	–	–	–	–	0.0	–	25.5	0.0
Low Fidelity Photo	clean	2.53	2.80	–	–	–	42.7	2282	–	41	–	–	–	–	0.0	–	0.0	0.0
Low Fidelity Photo	aliased	2.53	2.78	–	–	–	36.5	1498	–	44	–	–	–	–	0.0	–	0.0	0.0
Low Fidelity Photo	blurred	2.35	2.75	–	–	–	29.0	2005	–	42	–	–	–	–	0.0	–	0.0	0.0
Low Fidelity Photo	noisy	2.70	2.85	–	–	–	32.0	1926	–	41	–	–	–	–	0.0	–	0.0	0.0
Low Fidelity Photo	scanned	1.95	2.04	–	–	–	34.5	2548	–	39	–	–	–	–	0.0	–	0.0	0.0
3 Colors	clean	0.06	2.00	0.070	0.31	0.30	2.0	11	1.78	39	100	0.0	0.0	0	0.0	0.0	0.0	0.0
3 Colors	aliased	0.13	8.77	0.242	0.91	0.91	2.0	12	2.00	39	100	0.0	0.0	0	0.0	0.0	0.0	0.0
3 Colors	blurred	0.34	7.83	0.073	0.24	0.24	2.0	9	1.50	39	100	0.0	0.0	0	0.0	0.0	0.0	0.0
3 Colors	noisy	0.71	2.03	0.114	0.32	0.32	2.0	11	1.83	39	100	0.0	0.0	0	0.0	0.0	0.0	0.0
3 Colors	scanned	1.57	3.22	0.089	0.30	0.30	2.0	12	2.00	39	100	0.0	0.0	0	0.0	0.0	0.0	0.0
6 Colors	clean	0.12	2.70	0.057	0.31	0.30	3.0	28	2.00	43	100	0.0	0.0	0	0.0	0.0	0.0	0.0
6 Colors	aliased	0.29	10.43	0.298	1.00	1.00	3.0	27	2.05	43	100	0.0	0.0	0	0.0	0.0	0.0	0.0
6 Colors	blurred	0.62	9.33	0.204	1.34	1.19	6.0	98	5.46	39	50	16.0	0.0	0	0.6	0.0	0.0	0.0
6 Colors	noisy	0.85	2.58	0.076	0.52	0.58	3.0	34	2.34	28	88	0.0	0.0	0	0.3	0.3	0.0	0.0
6 Colors	scanned	1.74	4.42	0.228	1.20	0.94	7.0	108	6.10	28	62	20.5	0.0	0	0.8	1.6	0.0	0.0
16 Colors	clean	0.12	2.52	0.052	0.31	0.30	3.0	28	2.11	43	100	0.0	0.0	0	0.0	0.0	0.0	0.0
16 Colors	aliased	0.29	10.38	0.290	1.00	1.00	3.0	31	2.25	43	100	0.0	0.0	0	0.0	0.0	0.0	0.0
16 Colors	blurred	0.63	9.38	0.215	1.31	1.19	7.0	132	7.21	42	50	21.0	0.0	0	0.0	0.0	0.0	0.0
16 Colors	noisy	0.85	2.56	0.075	0.52	0.58	3.0	35	2.45	27	88	0.0	0.0	0	0.2	0.2	0.0	0.0
16 Colors	scanned	1.72	4.43	0.256	1.09	0.96	7.5	151	8.31	33	62	24.0	0.0	0	1.2	1.2	0.0	0.0
Shades of Gray	clean	9.71	9.55	–	–	–	18.2	748	–	51	–	–	–	–	0.0	–	0.5	0.0
Shades of Gray	aliased	9.71	9.52	–	–	–	11.0	642	–	57	–	–	–	–	0.0	–	0.5	0.0
Shades of Gray	blurred	9.66	9.32	–	–	–	11.5	577	–	55	–	–	–	–	0.0	–	0.5	0.0
Shades of Gray	noisy	9.74	9.45	–	–	–	19.5	643	–	45	–	–	–	–	0.0	–	0.0	0.0
Shades of Gray	scanned	6.58	6.46	–	–	–	19.0	762	–	47	–	–	–	–	0.0	–	1.0	0.0
Black and White Logo	clean	0.04	1.64	0.027	0.50	1.24	1.4	19	1.90	50	89	0.0	–	–	–	–	0.0	0.0
Black and White Logo	aliased	0.39	20.35	0.172	1.02	1.35	1.4	22	2.32	53	96	0.0	–	–	–	–	0.0	0.0
Black and White Logo	blurred	0.80	16.29	0.045	0.82	2.15	1.4	38	3.62	21	21	0.9	–	–	–	–	0.0	0.0
Black and White Logo	noisy	1.72	3.90	0.028	0.51	1.24	1.4	22	2.18	40	67	0.0	–	–	–	–	0.0	0.0
Black and White Logo	scanned	15.05	20.10	0.115	0.86	2.17	1.4	51	5.02	11	25	0.9	–	–	–	–	0.0	0.0
Sketched Art	clean	0.19	5.64	0.111	0.80	52.93	1.9	18	1.49	19	100	0.0	–	–	–	–	0.0	0.0
Sketched Art	aliased	0.46	19.57	0.213	1.00	105.53	1.6	11	1.10	26	100	0.0	–	–	–	–	0.0	0.0
Sketched Art	blurred	1.07	19.72	0.274	0.70	105.49	1.6	17	1.53	10	50	0.0	–	–	–	–	0.0	0.0
Sketched Art	noisy	1.76	6.16	0.119	0.95	1.03	2.0	19	1.58	12	100	0.0	–	–	–	–	0.0	0.0
Sketched Art	scanned	15.12	22.50	0.442	0.86	105.27	1.6	20	1.65	2	50	0.0	–	–	–	–	0.0	0.0
Silhouettes	clean	0.36	14.54	0.282	0.71	0.71	1.2	12	1.34	15	100	0.0	–	–	–	–	0.0	0.0
Silhouettes	aliased	0.39	21.69	0.289	1.00	1.00	1.2	9	0.99	12	100	0.0	–	–	–	–	0.0	0.0
Silhouettes	blurred	1.21	28.11	0.785	1.45	1.92	1.2	15	1.82	11	25	0.0	–	–	–	–	0.0	0.0
Silhouettes	noisy	2.11	10.96	0.284	0.69	0.69	1.2	11	1.27	7	100	0.0	–	–	–	–	0.0	0.0
Silhouettes	scanned	16.05	30.19	1.458	2.23	2.21	1.2	25	3.37	3	0	1.2	–	–	–	–	0.0	0.0
Line Art	clean	0.54	4.39	0.049	0.47	105.75	3.3	35	1.77	41	–	–	–	–	–	–	0.0	0.0
Line Art	aliased	0.67	14.44	0.112	0.73	55.44	14.0	59	2.95	87	–	–	–	–	–	–	0.0	0.0
Line Art	blurred	1.63	17.15	0.136	0.89	105.57	3.0	143	7.15	4	–	–	–	–	–	–	0.0	0.0
Line Art	noisy	1.04	4.35	0.045	0.48	56.06	8.0	53	2.65	38	–	–	–	–	–	–	1.0	0.0
Line Art	scanned	13.60	20.06	0.214	0.91	105.64	3.0	188	9.40	1	–	–	–	–	–	–	0.0	0.0
Technical Drawing	clean	0.17	2.83	0.054	0.50	55.75	5.1	27	1.79	90	91	0.0	–	–	–	–	2.1	0.0
Technical Drawing	aliased	0.43	18.51	0.204	1.02	55.44	6.8	33	2.06	95	94	0.0	–	–	–	–	0.0	0.0
Technical Drawing	blurred	1.04	16.59	0.082	1.06	105.75	2.0	114	7.50	24	28	2.3	–	–	–	–	0.0	0.0
Technical Drawing	noisy	1.42	4.30	0.055	0.50	31.23	7.8	38	2.40	85	90	0.0	–	–	–	–	2.8	0.0
Technical Drawing	scanned	14.45	20.15	0.144	0.91	105.74	2.0	123	8.33	23	34	2.3	–	–	–	–	0.0	0.0
Flat Logo	clean	0.07	1.53	0.065	0.31	0.27	3.0	36	3.51	47	100	0.0	0.0	0	6.8	–	0.0	0.0
Flat Logo	aliased	0.13	5.87	0.218	0.65	0.65	3.0	31	1.96	44	50	0.0	0.0	0	5.8	–	0.0	0.0
Flat Logo	blurred	0.54	8.33	0.052	0.62	0.78	3.0	28	1.78	43	50	0.0	0.0	0	5.8	–	0.0	0.0
Flat Logo	noisy	0.81	1.77	0.076	0.39	0.32	3.5	44	2.63	31	100	1.0	0.0	0	6.9	–	0.5	0.0
Flat Logo	scanned	1.31	4.15	21.204	88.50	0.66	470.5	2251	255.53	11	62	1658.0	0.0	0	58.0	–	413.5	0.2

4. Yardstick

Inkscape 1.4.2's Trace Bitmap, run as a black box through its object-trace action (two scans, background removed, its other settings as they come) on the same one-colour drawings, and its SVG output measured by the same code. Compare with the black-and-white presets on the same kinds of input in section 2 and 3.

inputs	variant	ΔE	edge ΔE	off mean	off max	missed max	paths	anchors	× art	lines %	corners %	kinks	odd colours	odd px	gap px	overlap px	outside px
curved shapes	clean	0.25	11.05	0.198	0.97	0.97	1.0	15	1.98	11	83	1.8	–	–	–	–	0.0
curved shapes	aliased	0.38	20.79	0.192	0.88	0.88	1.0	16	1.88	14	50	1.8	–	–	–	–	0.0
curved shapes	blurred	0.79	16.57	0.182	0.86	1.14	1.0	15	1.84	6	0	1.8	–	–	–	–	0.0
curved shapes	noisy	2.01	8.14	0.191	0.93	0.93	1.0	17	2.06	10	75	2.8	–	–	–	–	0.0
curved shapes	scanned	15.31	20.22	0.191	0.97	1.14	1.0	16	1.98	7	0	2.0	–	–	–	–	0.0
polygons	clean	0.16	6.45	0.124	1.26	2.36	1.0	21	1.93	27	34	0.0	–	–	–	–	0.0
polygons	aliased	0.35	18.33	0.150	1.22	2.35	1.0	20	1.81	20	28	0.0	–	–	–	–	0.0
polygons	blurred	0.90	17.54	0.190	1.20	2.56	1.0	19	1.75	0	0	0.0	–	–	–	–	0.0
polygons	noisy	1.62	6.05	0.119	1.22	2.32	1.0	22	2.01	29	19	0.0	–	–	–	–	0.0
polygons	scanned	14.75	20.30	0.170	1.49	2.55	1.0	21	1.90	4	3	0.0	–	–	–	–	0.0
thin lines	clean	0.44	6.05	0.109	0.98	76.81	1.0	34	1.72	2	–	–	–	–	–	–	0.0
thin lines	aliased	0.74	16.37	0.099	1.17	55.97	1.0	22	1.10	6	–	–	–	–	–	–	0.0
thin lines	blurred	1.72	18.80	0.254	0.81	106.00	1.0	18	0.90	0	–	–	–	–	–	–	0.0
thin lines	noisy	1.02	6.25	0.112	1.00	37.89	1.0	25	1.25	0	–	–	–	–	–	–	0.0
thin lines	scanned	28.94	46.83	12.147	43.11	20.79	1.0	2763	138.15	2	–	–	–	–	–	–	0.1

5. Cost

One trace at a time on this machine (all cores); memory is the peak allocated above the image itself. A trace of more than 2,000,000 anchors is refused, as in the app.

preset	image	megapixels	result
Default	photo-like	1	0.04 s, 29 paths, 6888 anchors, 15 MB
Default	four-colour badge	1	0.02 s, 3 paths, 96 anchors, 15 MB
High Fidelity Photo	photo-like	1	0.21 s, 968 paths, 114383 anchors, 238 MB
High Fidelity Photo	four-colour badge	1	0.06 s, 6 paths, 172 anchors, 36 MB
Low Fidelity Photo	photo-like	1	0.11 s, 129 paths, 22929 anchors, 144 MB
Low Fidelity Photo	four-colour badge	1	0.05 s, 6 paths, 136 anchors, 36 MB
3 Colors	photo-like	1	0.08 s, 9 paths, 3367 anchors, 26 MB
3 Colors	four-colour badge	1	0.05 s, 4 paths, 88 anchors, 21 MB
6 Colors	photo-like	1	0.08 s, 78 paths, 9008 anchors, 42 MB
6 Colors	four-colour badge	1	0.05 s, 5 paths, 84 anchors, 33 MB
16 Colors	photo-like	1	0.10 s, 178 paths, 20466 anchors, 102 MB
16 Colors	four-colour badge	1	0.05 s, 5 paths, 88 anchors, 33 MB
Shades of Gray	photo-like	1	0.08 s, 81 paths, 6698 anchors, 65 MB
Shades of Gray	four-colour badge	1	0.06 s, 10 paths, 733 anchors, 56 MB
Black and White Logo	photo-like	1	0.04 s, 71 paths, 5465 anchors, 9 MB
Black and White Logo	four-colour badge	1	0.02 s, 1 paths, 52 anchors, 8 MB
Sketched Art	photo-like	1	0.04 s, 5 paths, 2971 anchors, 9 MB
Sketched Art	four-colour badge	1	0.02 s, 2 paths, 131 anchors, 8 MB
Silhouettes	photo-like	1	0.04 s, 2 paths, 791 anchors, 11 MB
Silhouettes	four-colour badge	1	0.02 s, 1 paths, 25 anchors, 9 MB
Line Art	photo-like	1	0.04 s, 54 paths, 4421 anchors, 9 MB
Line Art	four-colour badge	1	0.02 s, 1 paths, 232 anchors, 8 MB
Technical Drawing	photo-like	1	0.04 s, 221 paths, 7680 anchors, 9 MB
Technical Drawing	four-colour badge	1	0.02 s, 1 paths, 52 anchors, 8 MB
Flat Logo	photo-like	1	refused after 0.09 s (not flat art), 40 MB
Flat Logo	four-colour badge	1	0.64 s, 5 paths, 78 anchors, 146 MB
Default	photo-like	4	0.18 s, 48 paths, 17801 anchors, 60 MB
Default	four-colour badge	4	0.09 s, 3 paths, 178 anchors, 64 MB
High Fidelity Photo	photo-like	4	0.72 s, 4475 paths, 341272 anchors, 981 MB
High Fidelity Photo	four-colour badge	4	0.24 s, 6 paths, 200 anchors, 152 MB
Low Fidelity Photo	photo-like	4	0.38 s, 304 paths, 61093 anchors, 568 MB
Low Fidelity Photo	four-colour badge	4	0.23 s, 6 paths, 152 anchors, 152 MB
3 Colors	photo-like	4	0.28 s, 20 paths, 8453 anchors, 104 MB
3 Colors	four-colour badge	4	0.18 s, 4 paths, 122 anchors, 84 MB
6 Colors	photo-like	4	0.37 s, 115 paths, 23128 anchors, 168 MB
6 Colors	four-colour badge	4	0.19 s, 5 paths, 92 anchors, 128 MB
16 Colors	photo-like	4	0.32 s, 353 paths, 52749 anchors, 408 MB
16 Colors	four-colour badge	4	0.19 s, 5 paths, 96 anchors, 128 MB
Shades of Gray	photo-like	4	0.29 s, 138 paths, 18794 anchors, 224 MB
Shades of Gray	four-colour badge	4	0.27 s, 10 paths, 1265 anchors, 220 MB
Black and White Logo	photo-like	4	0.20 s, 208 paths, 17188 anchors, 36 MB
Black and White Logo	four-colour badge	4	0.09 s, 1 paths, 64 anchors, 36 MB
Sketched Art	photo-like	4	0.20 s, 9 paths, 6884 anchors, 36 MB
Sketched Art	four-colour badge	4	0.09 s, 2 paths, 236 anchors, 36 MB
Silhouettes	photo-like	4	0.19 s, 2 paths, 1951 anchors, 44 MB
Silhouettes	four-colour badge	4	0.10 s, 1 paths, 32 anchors, 36 MB
Line Art	photo-like	4	0.19 s, 127 paths, 12091 anchors, 36 MB
Line Art	four-colour badge	4	0.09 s, 1 paths, 419 anchors, 36 MB
Technical Drawing	photo-like	4	0.20 s, 931 paths, 23132 anchors, 36 MB
Technical Drawing	four-colour badge	4	0.08 s, 1 paths, 64 anchors, 36 MB
Flat Logo	photo-like	4	refused after 0.10 s (not flat art), 40 MB
Flat Logo	four-colour badge	4	0.65 s, 5 paths, 69 anchors, 146 MB
Default	photo-like	16	1.04 s, 127 paths, 43656 anchors, 256 MB
Default	four-colour badge	16	0.47 s, 3 paths, 250 anchors, 240 MB
High Fidelity Photo	photo-like	16	2.85 s, 31125 paths, 1175671 anchors, 3856 MB
High Fidelity Photo	four-colour badge	16	1.11 s, 6 paths, 274 anchors, 576 MB
Low Fidelity Photo	photo-like	16	1.49 s, 2036 paths, 181832 anchors, 1972 MB
Low Fidelity Photo	four-colour badge	16	1.07 s, 6 paths, 187 anchors, 576 MB
3 Colors	photo-like	16	1.22 s, 76 paths, 22878 anchors, 416 MB
3 Colors	four-colour badge	16	0.82 s, 4 paths, 190 anchors, 336 MB
6 Colors	photo-like	16	1.13 s, 470 paths, 60539 anchors, 672 MB
6 Colors	four-colour badge	16	0.82 s, 5 paths, 126 anchors, 500 MB
16 Colors	photo-like	16	1.18 s, 1973 paths, 145173 anchors, 1625 MB
16 Colors	four-colour badge	16	0.84 s, 5 paths, 128 anchors, 504 MB
Shades of Gray	photo-like	16	1.48 s, 686 paths, 53872 anchors, 852 MB
Shades of Gray	four-colour badge	16	1.40 s, 9 paths, 2216 anchors, 800 MB
Black and White Logo	photo-like	16	1.15 s, 1128 paths, 52547 anchors, 144 MB
Black and White Logo	four-colour badge	16	0.47 s, 1 paths, 95 anchors, 128 MB
Sketched Art	photo-like	16	1.16 s, 15 paths, 16298 anchors, 144 MB
Sketched Art	four-colour badge	16	0.47 s, 2 paths, 414 anchors, 128 MB
Silhouettes	photo-like	16	1.34 s, 3 paths, 4516 anchors, 176 MB
Silhouettes	four-colour badge	16	0.53 s, 1 paths, 40 anchors, 144 MB
Line Art	photo-like	16	1.04 s, 713 paths, 43982 anchors, 144 MB
Line Art	four-colour badge	16	0.45 s, 1 paths, 707 anchors, 128 MB
Technical Drawing	photo-like	16	1.21 s, 4578 paths, 84475 anchors, 144 MB
Technical Drawing	four-colour badge	16	0.46 s, 1 paths, 95 anchors, 128 MB
Flat Logo	photo-like	16	refused after 0.11 s (not flat art), 40 MB
Flat Logo	four-colour badge	16	0.69 s, 5 paths, 67 anchors, 146 MB

Revision history

date	change
2026-10-13	Shared edges: outlines are cut at their junctions and each piece is fitted once, the same from either side
2026-10-13	Photos: continuous-tone images are smoothed within their tones before quantising, and stacked layers go by lightness
2026-10-13	The palette: made of the picture's own colours, noise-made colours merged, blend pixels settled, cuts where colours differ most, colours compared in Oklab
2026-10-13	Sub-pixel edges and the outline fitter in Black and White, Grayscale and Color; the harness gains an aliased variant and an "outside px" column, so the baseline was measured again with it (same tracer, main at `baf9693f`)
2026-10-12	The harness and the baseline: every preset measured before any change to the tracer

38 KiB Raw Blame History Unescape Escape