M13.1: lightcraft-merge crate — HDR merge, panorama stitching core
New L3 crate `crates/merge` (no UI deps), clean-room from published papers:
- features: Harris/MOPS-style oriented patch descriptors, ANMS, ratio-test matching
- ransac: normalised DLT homographies, similarity/translation, adaptive RANSAC
- hdr: brightness ordering, auto-align (model selection), robust exposure-ratio
estimation chained to the reference, saturation-aware weighted radiance merge,
deghost None/Low/Medium/High with feathered masks + overlay
- pano: pairwise matching, Brown–Lowe verification, focal from homographies,
rotation+focal bundle adjustment (LM), straightening, spherical/cylindrical/
perspective + auto, gain compensation, max-weight seams, multi-band blending
in log space, boundary warp, auto crop, fill edges (push–pull)
- output: LinearRaw DNG carrying source colour tags; raw crate gains Deflate
tiles (16/32-bit float with FP predictor, 16-bit int with predictor 2)
Tests: synthetic brackets (alignment < 0.3 px, EV < 0.02, radiance error
noise-limited, ghost removal) and synthetic panoramas (relative rotations
< 0.1°, focal < 1 %, error vs ground truth, seam test).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
543fdde41e