nx_natstat.nx

nx_natstat.nx -- NATURAL-IMAGE-STATISTICS photoreal metric = the REVERSE AI JUDGE. Real photographs have a signature our old critic missed: DETAIL AT EVERY SCALE (a ~1/f amplitude spectrum -> roughly EQUAL detail energy per octave). Clay/CG fails it two ways: too SMOOTH (fine + mid octaves empty) or GRAIN-ONLY (a spike at the finest octave, smooth beneath). We measure the multi-scale detail profile + its balance (+ gradient heavy-tail + colour spread) and return a graded PHOTOREAL LEVEL 0..1000. Uses: (a) REVERSE JUDGE: maximise this to push Z-Image toward more-real output for games/VR (evaluator-in-reverse); (b) "USE-AS-PHOTOREAL-TO-LEVEL": even a known-AI image is usable as photoreal up to the level it scores. Integer, deterministic, no FFT (Laplacian-pyramid octave energies). license_tier: ORIGINAL