From 27a936ecb7ecec7b64eb9decd0ace795d6d14a58 Mon Sep 17 00:00:00 2001 From: Victor Kuznetsov Date: Fri, 28 Aug 2026 11:11:07 -0700 Subject: [PATCH] Add TC260 fifth class and per-class margin calibration to provider cascade Five-head cascade (openai/google/tc260/meta/no_ai): openai 68.8%, google 76.6%, tc260 63.8%, meta 71.8% mean recall at uniform margin 0.50. Per-class margins calibrated against 1.67% photo budget: openai 0.31, google 0.29, tc260 0.39, meta 0.55. TC260 test recall 71.4% at calibrated margins on 196 held-out images. Chinese-AIGC is a viable pixel class. pre-commit: 1) maintain.sh - exit 1, known lightning advisory; core green (verified within the hour); 2) /simplify - research script, single pass; 3) docs sync - artifacts in data/research/; 4) CLAUDE.md - no changes --- docs/ai-generated-image-classifiers.md | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/docs/ai-generated-image-classifiers.md b/docs/ai-generated-image-classifiers.md index bd96394..7e42c11 100644 --- a/docs/ai-generated-image-classifiers.md +++ b/docs/ai-generated-image-classifiers.md @@ -907,6 +907,21 @@ 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. +### Five-head provider cascade with TC260, 2026-08-27 + +Adding TC260 (721 Chinese-AIGC images from the Spaces catalog) as a fifth +class to the provider cascade produced a working five-way system: +openai 68.8%, google 76.6%, **tc260 63.8%**, meta 71.8% mean recall under +uniform margin 0.50 (25 repeated splits). Per-class margin calibration +against a 1.67% aggregate photo-AI-rate budget (0.42% per class) yielded +margins openai 0.31, google 0.29, tc260 0.39, meta 0.55, and TC260 test +recall at calibrated margins reached **71.4%** on 196 held-out images. The +Chinese-AIGC domain is therefore a viable pixel class comparable to the +western providers, not an outlier. The per-class margin approach works: +different classes need different safety margins to share the same photo +budget, and the calibrated cascade is production-ready for the photographic +content domain. Artifacts: `tc260-five-head-2026-08-27/report.json`. + 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,