Merge PR #2009: Kelvin white balance from Canon CR2 ColorData presets (PowerShot G1 X Mark III)

docs/raw-parity.md: header change note and revision rows keep both sides (newest first).

docs/camera-preview-colour.md

@@ -52,6 +52,8 @@ Vendor RGB WB multipliers alone do **not** identify an absolute illuminant witho
 
 **Kelvin through the camera's white-balance presets.** Sony ARWs store, in the encrypted `SR2SubIFD`, the multipliers of every white-balance preset, five of them at a stated temperature (2500, 3200, 4500, 6000 and 8500 K). For a camera without measured matrices whose files carry them (`lightcraft_raw::kelvin_presets`: Sony ILCA-99M2, ILCA-77M2, SLT-A33, DSC-RX10, ILCE-3500, ILCE-7S) they take the matrices' place in everything above: the as-shot multipliers are placed on the curve through the five presets (mired linear along it, in log red/green and blue/green), an offset from the curve is the tint, and the decision, the Bradford adaptation, the pixel-identical upgrade and `Op::SetAsShotWb` are the same. The scale is Sony's own: files shot on the Kelvin setting read back what the dial said (ILCA-77M2 3400 K → 3396 K and 5200 K → 5193 K, SLT-A33 4700 K → 4708 K, the public ILCE-3500 sample's 5600 K → 5594 K; with the colour filter one step towards magenta, the SLT-A33's 3400 K reads 3473 K / +11), and the Shade preset reads 7493 K on the public ILCE-7S sample. Off the curve, two constants come from the 14 Sony bodies that have both measured matrices and presets: the tint is the offset scaled by the locus's own spacing (the matrices give 0.90–1.04 of it), and the isotherms lean against the curve's normal (`ISOTHERM_TILT` 0.74, measured 0.59–0.84). On 150 ILCE-7SM2 photos read both ways, the presets' temperature tracks the matrices' to ±4 mired around Sony's 8 % higher scale, and the tint to −9 ± 4. A listed camera whose file has no presets keeps the Kelvin scale with As Shot at D65, as a covered camera without multipliers does. Bodies with measured matrices keep reading through them.
 
+Canon CR2s list their presets by name in the maker note's `ColorData` (`0x4001`), each with Canon's colour temperature for it: for versions -4 and 13–15 the curve is built the same way from the Daylight, Shade, Cloudy, Tungsten and Flash rows (sorted by temperature; Fluorescent, a green light off the locus, and the Kelvin row, which holds the dial's last setting, are left out). Only the PowerShot G1 X Mark III is enabled, checked on a reporter's nine photos, one per white-balance setting: the as-shot levels read 4160 / 4580 / 5995 / 5215 / 2816 / 3703 / 7162 / 5368 / 4813 K (Auto, Daylight, Shade, Cloudy, Tungsten, Fluorescent at tint +31, Flash, Underwater, Kelvin 5500) where the camera's own `ColorTempAsShot` says 4306 / 4703 / 6005 / 5272 / 2770 / 3533 / 7100 / 5347 / 4925 K. Those photos were shot with the white-balance shift 8 steps (of 9) towards blue (`WBShiftAB` −8), which is why a Daylight shot reads about 4600 K and not the Daylight preset's 5651 K: the levels the camera applied are bluer than the preset's, and the camera's own number agrees.
+
 What the matrices say is not verified against Lightroom's Kelvin. On the ILCE-7M3 a Color Temp. series reads 7–10 % below Sony's dial through them, smoothly and monotonically, with tint near the locus (issue #730); whether the matrices or the dial are off is open (a grey card under an incandescent bulb would tell, since the Illuminant A matrix is exact there by construction). Public samples: ILCE-7M3 AWB 4268 K / +7, ILCE-7M4 AWB 4344 K / +26, GFX100S on its Daylight preset 4659 K / +9 (Fujifilm's nominal daylight is about 5300 K: the same direction and size of gap).
 
 Sony's proprietary `ColorMatrix` is not assumed to be a DNG XYZ-to-camera matrix. No Adobe profile/matrix or GPL decoder/calibration source is used. The product remains pure Rust.

docs/parity-checklist.md

@@ -193,7 +193,7 @@ differences and missing bindings are in [ui-parity.md](ui-parity.md#shortcuts).
 | LR-EDIT-LIGHT-CURVE-TAT | Drag-on-image curve adjust | P1 | ✅ | `cmd:develop.targeted` (`target: curve`) | |
 | LR-EDIT-COLOR-WB-PRESET | White-balance presets | P0 | ✅ | `cmd:develop.wb` | |
 | LR-EDIT-COLOR-WB-PICKER | White-balance eyedropper | P0 | ✅ | `cmd:tool.wbPicker`, `cmd:develop.wbPick`, `crates/ui-egui/src/tests_wb_selector.rs` | the Edit panel's selector button does what W does (from Compare, Survey or the grid it opens the photo in Detail); no magnified loupe while picking |
-| LR-EDIT-COLOR-TEMP | Temperature | P0 | ✅ | `ctl:wb.temp`, `crates/pipeline/src/local.rs` (`wb_matrix_for`, `legacy_white`), `crates/raw/src/color.rs` (`rebalance`), `crates/raw/src/spectral.rs` (`find_camera`), `crates/catalog/src/model.rs` (`relative_wb_camera`), `crates/develop/src/controls.rs` (`ControlSpec::position`), `crates/raw/src/kelvin_presets.rs` | Kelvin (2000–50000 K, As Shot read from the file) on raws with colour matrices: in the file (DNG: re-developed for the chosen white through the camera's own matrices, camera-space white balance as Lightroom; the eyedropper / Auto invert the same model) or measured for the camera model (`lightcraft_raw::spectral`, 52 bodies, issue #730: the matrices turn the as-shot multipliers into Kelvin and the slider back, the look stays the file's fit, and the picture is adapted from the as-shot white, Bradford), or read from the camera's own white-balance presets (Sony ARW `SR2SubIFD`, Sony ILCA-99M2, ILCA-77M2, SLT-A33, DSC-RX10, ILCE-3500, ILCE-7S: Sony's Kelvin dial reads back within 0.3 % on 5 settings of 4 bodies); raws without matrices anywhere and rendered files use the relative −100..+100 scale (6500 K / 0 = as shot). The Kelvin slider's track is Lightroom's: 7000 K in the middle, 2000–7000 K evenly on the left half, logarithmic up to 50000 K on the right (within 2 % of positions measured in Lightroom Classic), for drawing, clicks and drags; wheel / arrow-key nudges and Quick Develop still step a fixed 50 / 100 / 500 K; the relative slider stays linear. Settings written on the relative scale before a camera's matrices reached it keep their look (`WbScale`). Not verified against Lightroom's Kelvin: on the ILCE-7M3 the matrices read 7–10 % below Sony's dial (issue #730), and whether the matrices or the dial are off is open; raws without matrices or presets anywhere and rendered files use the relative −100..+100 scale (6500 K / 0 = as shot). Settings written on the relative scale before a camera's matrices reached it keep their look (`WbScale`). Not verified against Lightroom's Kelvin: on the ILCE-7M3 the matrices read 7–10 % below Sony's dial (issue #730), and whether the matrices or the dial are off is open |
+| LR-EDIT-COLOR-TEMP | Temperature | P0 | ✅ | `ctl:wb.temp`, `crates/pipeline/src/local.rs` (`wb_matrix_for`, `legacy_white`), `crates/raw/src/color.rs` (`rebalance`), `crates/raw/src/spectral.rs` (`find_camera`), `crates/catalog/src/model.rs` (`relative_wb_camera`), `crates/develop/src/controls.rs` (`ControlSpec::position`), `crates/raw/src/kelvin_presets.rs` | Kelvin (2000–50000 K, As Shot read from the file) on raws with colour matrices: in the file (DNG: re-developed for the chosen white through the camera's own matrices, camera-space white balance as Lightroom; the eyedropper / Auto invert the same model) or measured for the camera model (`lightcraft_raw::spectral`, 52 bodies, issue #730: the matrices turn the as-shot multipliers into Kelvin and the slider back, the look stays the file's fit, and the picture is adapted from the as-shot white, Bradford), or read from the camera's own white-balance presets (Sony ARW `SR2SubIFD`, Sony ILCA-99M2, ILCA-77M2, SLT-A33, DSC-RX10, ILCE-3500, ILCE-7S: Sony's Kelvin dial reads back within 0.3 % on 5 settings of 4 bodies; Canon CR2 `ColorData` presets, PowerShot G1 X Mark III: the camera's own As Shot temperature reads back within 5 % on its 9 white-balance settings). The Kelvin slider's track is Lightroom's: 7000 K in the middle, 2000–7000 K evenly on the left half, logarithmic up to 50000 K on the right (within 2 % of positions measured in Lightroom Classic), for drawing, clicks and drags; wheel / arrow-key nudges and Quick Develop still step a fixed 50 / 100 / 500 K; the relative slider stays linear. Settings written on the relative scale before a camera's matrices reached it keep their look (`WbScale`). Not verified against Lightroom's Kelvin: on the ILCE-7M3 the matrices read 7–10 % below Sony's dial (issue #730), and whether the matrices or the dial are off is open; raws without matrices or presets anywhere and rendered files use the relative −100..+100 scale (6500 K / 0 = as shot). |
 | LR-EDIT-COLOR-TINT | Tint | P0 | ✅ | `ctl:wb.tint`, `docs/tint-direction.md` | DNG / Lightroom sign: negative (left) adds green, positive (right) magenta; XMP `crs:Tint` values render as in Lightroom (issue #188); CPU/GPU regression tests |
 | LR-EDIT-COLOR-VIBRANCE | Vibrance | P0 | ✅ | `ctl:color.vibrance` | |
 | LR-EDIT-COLOR-SATURATION | Saturation | P0 | ✅ | `ctl:color.saturation` | |

docs/raw-parity.md

@@ -1,6 +1,6 @@
 # RAW parity: cameras, formats, demosaic, colour and lens profiles
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-18 · **Change:** minor (lossy JPEG XL DNG tiles with a non-linear declared transfer curve decode; X-Trans CMOS 4 bodies take the X-T3's spectral matrices) · **Target:** Adobe Lightroom Classic 15.5 / Lightroom 9.6 (Camera Raw 18.7)
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-18 · **Change:** minor (lossy JPEG XL DNG tiles with a non-linear declared transfer curve decode; Canon ColorData Kelvin; X-Trans CMOS 4 bodies take the X-T3's spectral matrices) · **Target:** Adobe Lightroom Classic 15.5 / Lightroom 9.6 (Camera Raw 18.7)
 
 Raw processing is the deepest single dimension of Lightroom parity: a photographer whose camera
 does not decode, or decodes with the wrong colour, cannot switch. This document measures it model by
@@ -209,7 +209,7 @@ sample files. A pointer for contributors, not legal advice.
 | Camera Matching looks | 481 models (plus phone-maker looks) | none (the per-file JPEG fit imitates the camera's own look) |
 | Creative profiles | Adobe Color, Portrait, Landscape, Vivid, Monochrome… | our own looks (Color, Neutral, Vivid, Landscape, Portrait, Monochrome) |
 | DCP / dual-illuminant model | ✅ | dual-illuminant DNG colour (ColorMatrix / ForwardMatrix 1-2, CameraCalibration, AnalogBalance), HueSatMap, LookTable, ProfileToneCurve; external `.dcp` never loaded (clean-room) |
-| White balance in Kelvin | ✅ for every model | absolute Kelvin where the camera has colour matrices (its own, or one of the 52 spectral rows), also for files whose look is a per-file fit (#730), or where Sony's white-balance presets in the file give the scale (6 bodies, `kelvin_presets`); other raws keep the relative scale (#296) |
+| White balance in Kelvin | ✅ for every model | absolute Kelvin where the camera has colour matrices (its own, or one of the 52 spectral rows), also for files whose look is a per-file fit (#730), or where the camera's white-balance presets in the file give the scale (6 Sony bodies and the Canon PowerShot G1 X Mark III, `kelvin_presets`); other raws keep the relative scale (#296) |
 
 **How far the default rendering is from Adobe's** (CIE ΔE; measured where stated):
 
@@ -288,6 +288,7 @@ Beyond decoding:
 | Date | Change | Summary |
 |---|---|---|
 | 2026-10-18 | patch | X-T30, X-T30 II, X-Pro3, X100V, X-S10 and X-E4 take the X-T3's spectral matrices (same 26.1 MP X-Trans CMOS 4 sensor): an X-T30 raw with a black-and-white (Acros) camera JPEG no longer opens in the muted neutral fallback |
+| 2026-10-16 | minor | Kelvin white balance from Canon CR2 `ColorData` presets (PowerShot G1 X Mark III) |
 | 2026-10-15 | minor | DNGs with a look table and no tone curve (Lightroom-written, Adobe Standard) fit their tone to the embedded preview, also Lightroom's 1024 px one: two lossy ILCE-7CM2 DNGs no longer render 0.8 EV dark and flat |
 | 2026-10-15 | minor | Lossy JPEG XL DNG tiles that declare a non-linear SDR transfer curve (sRGB, BT.709, DCI, gamma) decode with that curve restored instead of falling back to the embedded preview: Lightroom Classic 15.1 LinearRaw DNGs (Rec. 2100 primaries, sRGB curve; 2 private ILCE-7CM2 files) |
 | 2026-10-15 | minor | Hasselblad 3FR / FFF embedded previews: the uncompressed 8-bit RGB image, handed on as a baseline TIFF (checked on the CC0 H4D-40 FFF, 1217 × 913, and CFV 3FR, 218 × 218, upright through the file's orientation); counts unchanged |