vendor::arw_lens_rm6::warp_opcode (was distortion_opcode) turns the CA table
(0x7035: red half, blue half, on the distortion knots) into the R and B
planes of the WarpRectilinear: a colour's source radius is
g (1 + c(g) / 3.36e6) at the green source radius g. The unit is provisional
(borderline measurement, about +-30 % scene bias). Each colour plane goes
through the same fit gate as G, and a table with a value beyond 2e-3 relative
(about 12 px at the full-frame corner; the 54 photos' tables stay below
5.1e-4, i.e. 1724) is refused; without a CA table, or when it is refused, the
warp keeps its single G plane, and CA alone is never applied. fit_radial_warp
now rounds its gate up to the next sample, capped at 1 (a NaN gates every
sample), so the band between the last sample inside the crop and the crop
corner is checked too (RW2 passes 1.0: unchanged).
Co-Authored-By: Claude <noreply@anthropic.com>
New vendor::arw_lens_rm6 reads the raw IFD's lens tables (0x7037 distortion,
0x7032 vignetting, 0x7035 lateral CA, their flags) and turns the distortion
table into a one-plane WarpRectilinear in OpcodeList3, with the conventions
measured on 54 ILCE-7RM6 photos: knots at i/15 of the full-frame crop half
diagonal, S(r) = r (1 + v(r)/15000), frame-filling zoom, centred on the
default crop. Only the ILCE-7RM6 is enabled; vignetting is read, not applied.
The radial least-squares fit is split out as vendor::fit_radial_warp (RW2
results unchanged); its error gate can be limited to the radii the crop
shows, so a padded active area (lossless files) doesn't refuse a fit over
pixels that are never rendered.
It sits next to main's vendor::arw_lens (#498), which holds the ILCE-7RM4A
conventions measured against Sony's exports (unit 16384, table indexed at the
output radius); the two are selected by camera model (disjoint allowlists).
arw::decode chains this module's opcodes after arw_lens::distortion, with the
same active area and the same crop (the DNG-style default crop when the file
has one, which on the ILCE-7RM6 equals Sony's crop tags), and like it only
for CFA data (not the downsized linear-RGB lossless sizes, where the knot
spacing in full-frame pixels would not hold).
The corpus test checks the conversion on the two lossless RawDB files (CC0).
The APS-C one is pinned in xtask RAW_SAMPLES with its sha256; the full-frame
one is not (at most two pins per PR, and #625 pins two Compressed ARW 6.0
files), so its case runs only where the file is present.
RENDER_CACHE_VERSION 62 -> 63.
Co-Authored-By: Claude <noreply@anthropic.com>
Move the forward-map inversion, least-squares fit and solve4 out of the RW2
decoder into vendor::warp_from_forward_map; RW2 calls it in DNG-normalised units.
Co-Authored-By: Claude <noreply@anthropic.com>
