Files
DarkRoom/core/dr-decode/Cargo.toml
dtourolleandClaude Opus 5 743fefe7f1 Render each body through the profile its own files describe
Colour came from whichever matrix rawler happened to key `D65`, the second
one was discarded, and the rendering was left linear. That is the dcraw
default, and FR-DEV-3e names it as the reason people abandon a converter in
the first hour: correct in the abstract, flat and poor on skin in practice.

The decoder now builds a camera profile.

- `ColorMatrix1/2` and `CalibrationIlluminant1/2`. rawler surfaces these as
  an illuminant-keyed map — for DNGs from the tags, and for native formats
  from its own camera database — so a Canon CR2 arrives with a tungsten
  matrix and a daylight matrix exactly as an Adobe DNG of the same frame
  would. Dual-illuminant support is therefore not a DNG feature here.

- `ForwardMatrix1/2`, read straight from the root IFD, because rawler parses
  them and never surfaces them. Where a file carries both, they replace the
  inverted colour matrix: the same relationship measured in the direction
  rendering actually wants, rather than an inversion that amplifies the
  measurement error exactly where skin lives.

- `AsShotNeutral`, used to estimate what the scene was lit by and to
  interpolate between the two calibrations in mireds. The estimate is
  circular — the temperature needs a matrix and the matrix needs the
  temperature — so it is a fixed point, three rounds, as Adobe's SDK does it.

Bodies calibrated at neither D65 nor A stopped rendering uncalibrated as a
side effect: a Phase One IQ3 carries D55 and D75 and used to get no matrix
at all.

And a base curve, applied per channel in camera RGB between the last
adjustment and the conversion out of camera space — a toe, a steep midtone
and a shoulder, which is the difference between a photograph and a scan of
one. It is not an edit: no slider, nothing in the sidecar, because it
belongs to the body rather than to anything anyone decided, and a sidecar is
shared between bodies. It is not a develop node either, and `ops/README.md`
now records why. It evaluates on the tone curve's own spline rather than a
second copy, so a profile author placing a control point and a photographer
dragging one mean the same thing by it.

The curves are data. `core/dr-decode/profiles/base_curves.yaml` ships inside
the binary as a floor and is superseded by any copy on disk carrying a
higher `version:`, so a body can be added and distributed without a release
— and, under the GPL, contributed. The comparison runs both ways: a stale
pack cannot hold an upgraded binary back at last year's rendering.

Canon EOS 6D and R6, Nikon Z 6 and D750, Sony A7 III and Fujifilm X-T3 ship
with their own curves. Every other body gets a conservative default, which
is much closer to right than the identity is for any of them. A JPEG gets
none — it has already been rendered once, by the camera.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-22 14:37:33 +02:00

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TOML

[package]
name = "dr-decode"
version.workspace = true
edition.workspace = true
rust-version.workspace = true
license.workspace = true
[dependencies]
dr-types.workspace = true
rawler.workspace = true
# The camera profile database is data, not code (FR-DEV-3e): a YAML file that
# ships with the binary and is superseded by a newer one on disk. serde_norway
# is the workspace's YAML crate — the fork still receiving releases — and it is
# already in the tree for `dr-pipeline`'s node declarations and `dr-ui`'s style
# tokens. Pure Rust, so it costs nothing under the Android NDK.
serde = { workspace = true }
serde_norway.workspace = true
zune-jpeg.workspace = true
thiserror.workspace = true
log.workspace = true
[dev-dependencies]
env_logger.workspace = true