umangkaushik17-bit/balancing-primary-color-and-skins

Primary Color Balancing & Shot-Matching Skill

When to Use This Skill

• Before applying any creative look or aesthetic grade in Premiere Pro.
• When A-roll talking-head clips and B-roll cutaways have mismatched lighting, exposure, or color temperature.
• When raw footage looks washed out (Log/Flat), underexposed, or has an indoor tungsten/outdoor blue cast.

Step 1: Run Virtual Scopes Telemetry (Active Picture Only)

1. Export representative frames from each timeline clip (or point directly to clip frame folders in 02_analysis/clip_frames/) and run:

   python .agents/skills/balancing-primary-color-and-skins/scripts/virtual_scopes.py --frames_dir 02_analysis/clip_frames --output 02_analysis/color_telemetry.json --match_to <hero_clip_stem>
   

2. By default (auto_crop_active=True), extract_active_region automatically strips static black letterbox/pillarbox/windowbox bars before calculating IRE percentiles so black bars never drag p01_black or p50_mid down to zero. Pass --no_crop_active only when inspecting explicit full-frame matting plates.
3. Read 02_analysis/color_telemetry.json:
   • active_region: verified cropped bounding box [x, y, w, h] vs full_size.
   • luma_ire: p01_black, p25_shadow, p50_mid, p75_high, p99_white, dynamic_range.
   • rgb_parade_cast: r_bias, g_bias, b_bias in neutral midtones.
   • skin_metrics: skin_detected, skin_luma_ire (55-70 IRE), YCrCb shifts.
   • environment_metrics: mean_saturation_pct, green_fraction, sky_blue_fraction, warm_fraction.
   • recommended_primary_lumetri: mathematically derived Pass 1 values (enforces highlight safety exposure <= 0 whenever p99_white > 94.0).

Step 2: Apply Pass 1 Primary Normalization (Tracks V1 & V2)

Apply each clip's recommended_primary_lumetri baseline via a base Lumetri Color effect before any global Track V4 creative grade.

Step 3: Pass 2 Shot-to-Shot Matching (match_delta_to_hero)

Designate the primary A-roll hero clip with --match_to <hero_clip> and apply match_delta_to_hero (exposure_delta, temperature_delta, tint_delta, contrast_delta, highlights_delta, shadows_delta, saturation_delta) across cutaways and multi-strip panels so all clips share cohesive exposure, temperature, and foliage green saturation before Track V4 styling.