Computational analysis of the photograph of the artwork C Major - Research on Harmony (AQC0621) [1] by Arnaud Quercy [2], according to IDS-CMP-2025 [3], on an image 1000 pixels on its longer side, on 2025-10-03. Each colour is located in the Munsell system and named according to the ISCC-NBS system (267 names, National Bureau of Standards, 1976). The image divides into 26 flat areas. The largest are strong yellow (26%), vivid red (24%) and vivid reddish orange (11%). Among the others, those that stand out most sharply from their surroundings are dark grayish olive on the right (8.1%), pinkish white in the centre (1.5%) and brownish black in the centre (1.3%). By colour name family: orange 32%, yellow 25%, red 21%, brown 7.4%, olive 5.4%, gray 1.9%, olive black 1.5%, orange yellow 1.4%, white 1.3% and black 1.1%.
Context
Analysis performed according to IDS-CMP-2025 [3]: (a) colours named by Munsell and ISCC-NBS, areas and flat areas, (b) texture, (c) brightness and contrast, (d) spatial distribution. Source image: 2372x3558 pixels. Analysis date: 2025-10-03.
A) Color Analysis
Flat areas
Ranked by contrast with their surroundings (CIEDE2000). Strokes thinner than 10 pixels are excluded (15).
| Rank |
Colour |
ISCC-NBS name |
Munsell |
Area |
Contrast |
Position |
| 1 |
2F2D25 |
dark grayish olive |
0.6GY 1.7/0.9 |
8.1% |
44.2 |
on the right |
| 2 |
E8E6E3 |
pinkish white |
2.1R 9.1/1.0 |
1.5% |
43.4 |
in the centre |
| 3 |
1C130E |
brownish black |
0.9Y 0.7/0.8 |
1.3% |
42.1 |
in the centre |
| 4 |
646965 |
dark greenish gray |
0.3G 4.4/0.9 |
0.3% |
41.3 |
at the top left |
| 5 |
35291E |
dark grayish olive |
4.3Y 1.8/1.8 |
0.2% |
39.3 |
at the top right |
| 6 |
706E6D |
reddish gray |
3.6R 4.5/0.7 |
0.4% |
28.1 |
at the top right |
| 7 |
802D33 |
dark red |
4.6R 3.1/7.9 |
2.1% |
26.5 |
on the left |
| 8 |
E3C636 |
strong yellow |
4.9Y 7.9/9.9 |
26% |
26.0 |
at the top left |
| 9 |
ED662C |
vivid reddish orange |
0.2YR 5.8/13.6 |
0.4% |
24.2 |
on the right |
| 10 |
E6601F |
vivid reddish orange |
1.2YR 5.7/13.6 |
11% |
22.9 |
at the top right |
| 11 |
5D5B5D |
dark gray |
N 3.8/ |
1.3% |
20.3 |
in the centre |
| 12 |
C97B30 |
moderate orange |
5.4YR 5.8/9.5 |
0.8% |
13.1 |
in the centre |
| 13 |
C0250F |
vivid red |
8.6R 4.2/15.2 |
24% |
11.0 |
at the bottom |
| 14 |
6F3D14 |
strong brown |
6.0YR 3.0/6.2 |
3.4% |
10.9 |
at the bottom |
| 15 |
A0410C |
dark reddish orange |
1.9YR 4.1/10.8 |
1.5% |
10.0 |
in the centre |
| 16 |
DA9D33 |
moderate orange yellow |
9.4YR 6.8/9.7 |
0.5% |
7.7 |
on the left |
| 17 |
D05032 |
strong reddish orange |
9.0R 5.1/12.3 |
0.3% |
6.6 |
on the right |
| 18 |
E25F0E |
vivid reddish orange |
0.9YR 5.5/14.5 |
6.1% |
5.3 |
in the centre |
| 19 |
CE3223 |
vivid reddish orange |
8.1R 4.5/14.2 |
3.6% |
1.9 |
at the bottom right |
| 20 |
C82A1C |
vivid red |
8.2R 4.4/14.9 |
0.2% |
1.5 |
at the bottom right |
| 21 |
C73123 |
vivid red |
8.2R 4.4/13.5 |
0.1% |
1.4 |
at the bottom right |
| 22 |
C72E22 |
vivid red |
7.7R 4.3/14.0 |
0.1% |
1.2 |
at the bottom right |
| 23 |
C62616 |
vivid red |
8.3R 4.2/15.0 |
0.1% |
1.1 |
at the bottom right |
| 24 |
EF6226 |
vivid reddish orange |
0.5YR 5.8/13.9 |
3.4% |
0.8 |
at the top right |
| 25 |
D13521 |
vivid reddish orange |
8.0R 4.7/14.9 |
0.7% |
0.3 |
at the bottom right |
| 26 |
CA3124 |
vivid reddish orange |
8.1R 4.5/14.2 |
0.5% |
0.3 |
at the bottom right |
Colour name families
| Family |
Area |
| orange |
32% |
| yellow |
25% |
| red |
21% |
| brown |
7.4% |
| olive |
5.4% |
| gray |
1.9% |
| olive black |
1.5% |
| orange yellow |
1.4% |
| white |
1.3% |
| black |
1.1% |
| olive brown |
0.7% |
B) Texture Analysis
| Metric |
Value |
| Global Roughness |
0.211 |
| Mean Local Roughness |
0.024 |
| Roughness Uniformity |
0.019 |
| Edge Density |
0.143 |
| Mean Gradient Magnitude |
0.199 |
| Gradient Variance |
0.045 |
| Gradient Smoothness |
0.0 |
| Directional Coherence |
0.009 |
| Pattern Complexity |
0.123 |
| Pattern Repetition |
1.0 |
| Detail Frequency Ratio |
0.625 |
| Spatial Variation |
0.165 |
| Texture Consistency |
0.484 |
C) Brightness & Contrast Analysis
| Metric |
Value |
| Mean Brightness |
0.47 |
| Brightness Variance |
0.211 |
| Brightness Uniformity |
0.55 |
| Brightness Skewness |
0.239 |
| Brightness Entropy |
7.55 |
| Rms Contrast |
0.211 |
| Michelson Contrast |
1.0 |
| Weber Contrast |
0.701 |
| Mean Local Contrast |
0.026 |
| Contrast Uniformity |
0.282 |
| Dynamic Range |
1.0 |
| Effective Dynamic Range |
0.655 |
| Shadow Percentage |
32.949 |
| Midtone Percentage |
41.593 |
| Highlight Percentage |
25.458 |
| Shadow Clipping |
0.012 |
| Highlight Clipping |
0.007 |
| Tonal Balance |
0.211 |
| Fine Contrast |
0.013 |
| Medium Contrast |
0.032 |
| Coarse Contrast |
0.051 |
| Multiscale Contrast Ratio |
0.267 |
| Edge Contrast |
0.199 |
| Contrast Clustering |
0.516 |
D) Spatial Distribution Analysis
| Metric |
Value |
| Spatial Coherence |
0.762 |
| Color Clustering |
0.492 |
| Color Transition Smoothness |
0.517 |
| Transition Uniformity |
0.704 |
| Sharp Transition Ratio |
0.1 |
| Transition Directionality |
0.011 |
| Mean Saturation |
0.753 |
| Saturation Variance |
0.056 |
| Low Saturation Ratio |
0.103 |
| Medium Saturation Ratio |
0.096 |
| High Saturation Ratio |
0.801 |
| Saturation Clustering |
0.998 |
| Hue Concentration |
0.946 |
| Complementary Balance |
0.0 |
| Analogous Dominance |
0.999 |
| Temperature Bias |
0.993 |
Methodology
Computational analysis of a photograph of the artwork, reduced to 1,000 pixels on its longer side and filtered by a 3×3 median to remove grain. Colours: each pixel (sRGB rounded to 5 bits per channel) receives its Munsell notation and ISCC-NBS name from a table computed once from published data (Munsell renotation; ISCC-NBS blocks, NBS Special Publication 440, 1976), never from the artworks. Flat areas: connected regions of one name, merged with their neighbours while the CIEDE2000 difference between their mean colours stays below 10; an area is kept from 0.05% of the image; contrast with the surroundings measured 4 to 12 pixels from the edge. Texture: intensity standard deviation, local standard deviation, edge density (Canny), local binary patterns. Brightness: mean, variance, RMS, Michelson and local contrast, shadow / midtone / highlight distribution. Distribution: spatial coherence, transitions, saturation. Methods are deterministic and reproducible. Limits: the measurement concerns the photograph, including its lighting and white balance; two neighbouring areas less than 10 apart are merged.
