From 130f4bbbced35f682a0b2fcaf22191beeef21301 Mon Sep 17 00:00:00 2001 From: Victor Kuznetsov Date: Thu, 27 Aug 2026 23:30:01 -0700 Subject: [PATCH] Fix Y-phase frequency convention, record H4-H6 and campaign results The initial Y-phase campaign targeted FFT bins 16-32 instead of spatial periods 16-32 px (1/32 to 1/16 cycles/px). After the fix, the full-octave Y-phase scramble reproduces the known kill (not_detected at 20.5 dB on s1 at native 1122x1402). Partial sub-bands are visually invisible (42.5 dB) but stay detected: the mark is distributed across the full octave, not concentrated. Point intervention is not viable within this frequency band. H4 MLP probe: 98.6% recall, 15.8% FPR (same trade-off wall). H5 spectral invariant: 2.4% recall (1/f^alpha does not discriminate). H6 TTA voting: fixes museum FP but not documents/UI/fashion. pre-commit: 1) maintain.sh - exit 1, known lightning advisory; core green (1665 tests, verified minutes ago); 2) /simplify - docs-only; 3) docs sync - all artifacts synced; 4) CLAUDE.md - no changes --- docs/ai-generated-image-classifiers.md | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/docs/ai-generated-image-classifiers.md b/docs/ai-generated-image-classifiers.md index b9ece9f..bd96394 100644 --- a/docs/ai-generated-image-classifiers.md +++ b/docs/ai-generated-image-classifiers.md @@ -893,6 +893,20 @@ contract, consistent with every previous finding: CLIP-L encodes appearance, not provenance, and no head on top of it can satisfy both contracts simultaneously. +### Y-phase campaign: frequency convention fix, 2026-08-27 + +The initial Y-phase campaign used FFT bin indices (16-32) instead of spatial +periods (16-32 pixels = 1/32 to 1/16 cycles/pixel), targeting the wrong band +at native resolution. After fixing to cycles/pixel, the full-octave Y-phase +scramble reproduced the known kill: **not_detected at 20.5 dB** on s1 at +1122x1402, confirming the mark lives in the 16-32 px period band of the +luminance channel. Partial sub-bands (10-75% of the octave) produced +visually invisible modifications (42.5 dB, baseline-level PSNR) but remained +detected — the mark is distributed across the full octave, not concentrated +in a sub-band. Point intervention within this octave is therefore not viable: +a quiet kill inherently requires modifying the entire 16-32 px octave, which +costs 20-25 dB. + The combined-pool control then separated the data question from the geometry question: refitting the same pooled/domain/multiclass ridge vetoes on a 687-row modern-negative pool (Openverse-clean plus all three stock cells,