The RW2 reader reads PanasonicRaw tag 0x0119 (16 LE words) and expresses the
camera's own correction as the equivalent DNG WarpRectilinear in OpcodeList3,
so embedded_lens() turns it into the existing EmbeddedLens/EmbeddedWarp and
"Enable Profile Corrections" applies it like a DNG's warp (no new warp path;
Convert to DNG keeps it). Rule, from our own measurements against the
embedded camera JPEGs (clean-room; ExifTool tag names only):
corrected = rho*(1 + (w8 rho^2 + w4 rho^4 + w11 rho^6)/32768), rho = r/w12
(w12 = active-area half diagonal), output = corrected / (1 + w5/32768),
on when (w7 & 0xf) == 1. Chosen on 38 GX85 photos, held out on 35 photos
from 12 other bodies / 9 other lenses; corrected renders line up with the
camera JPEG within 0.75 px at 1440 px at the corners (up to 13 % of the
half diagonal before). Implausible values leave the photo uncorrected.
The loader now removes lens opcodes before the RW2 camera-look fit (its
binned proxy needs an empty OpcodeList3); Opcode::is_lens_correction()
replaces the duplicated matches. RENDER_CACHE_VERSION 11 -> 12.
03bc1469f9