INDENTATION SPECTRAL ANALYSIS (ISA-1.0)
Definition
ISA-1.0 = INDENT-S only. Ink-suppress / indentation reveal is a synthetic
image-enhancement heuristic. It washes visible writing toward estimated
parchment and lifts paper-fiber / pressure relief already in the photograph.
This is not ESDA, not electrostatic detection apparatus, and not a claim of
recovering invisible writing with certainty. Prefer target=page. ink|page
both allowed.
Functional Behavior
A. Ink suppress:
   - Dark strokes are lifted toward the estimated page color.
B. Surface relief:
   - Band-pass / high-pass luminance emphasizes fibers and pressure dents
     that are already in the pixels.
C. Honesty:
   - No invented grooves. No forensic certification.
Operational Pipeline
1. Estimate parchment from the brightest quintile.
2. Wash ink toward that parchment color.
3. Mix in normalized relief from the original luminance.
4. Output ISA-1.0.
Usage
Commands that activate ISA-1.0:
- "Ink-suppress / indentation reveal"
- "Run indent on this page"
- "indentation" / "suppress-ink" / "ink-suppress" / "revealer-indent"
Author Aziel Eliab.
