smk-playground/docs/FEATURE_VECTOR_V1.md

Candidate feature vectors v1

artwork-feature-vectors-v1.parquet is a compact candidate dataset, not a similarity definition. It contains one row per corpus entity, completeness flags and three fixed-size list columns. Exact component order is embedded in the normalization profile and repeated below.

color_core_v1

1. raw centroid_l
2. raw centroid_a
3. raw centroid_b
4. palette_spread_oklab_robust_01
5. lightness_stddev_robust_01
6. chroma_stddev_robust_01
7. natural hue_concentration_01

Raw OKLab coordinates deliberately preserve perceptual meaning. Centroid hue x/y are excluded to avoid double-counting hue already represented by a/b.

visual_character_v1

1. smk_brightness_robust_01
2. smk_contrast_robust_01
3. smk_saturation_robust_01
4. smk_entropy_robust_01

smk_colortemp remains available in the wide normalized table but is excluded here.

geometry_v1

1. log_net_width_cm_robust_01
2. log_net_height_cm_robust_01
3. log_net_area_cm2_robust_01
4. log_net_aspect_ratio_robust_01

Geometry is optional and missing elements remain null. Raw area and raw aspect ratio are not vector components. No family has weights, and the three families are not concatenated into a final distance space. Later comparison may combine raw OKLab distance, normalized scalar distance, palette-level distance and optional geometry under separately versioned similarity profiles.

Milestone 5 consumes explicit scalar columns rather than treating these lists as an opaque universal vector. See SIMILARITY_V1.md for frozen component selection, scales and weights.