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Bug #8891

Darktable should read the D65 Color Matrix from DNGs when possible

Added by Pascal de Bruijn over 6 years ago.

Status:
Fixed
Priority:
Medium
Assignee:
-
Category:
Darkroom
Start date:
08/25/2012
Due date:
% Done:

100%

Affected Version:
git development version
System:
bitness:
64-bit
hardware architecture:
amd64/x86

Description

Currently Darktable doesn't read the D65 ColorMatrix from DNG files. Often this means people are stuck with the linear RGB color profile applied as input profile. With the end result being very dull files.

For a few camera's Leica M9/X1/X2 and some Ricoh models, I manually extracted those matrices and put them into our adobe_coeff's file, as a stop-gap measure.

So ideally we'd read the D65 matrix, with the following logic:

1. Is the RAW a DNG?
2. If yes, does the DNG contain a CalibrationIlluminant with type 21 (=D65)
3. If yes, load the corresponding ColorMatrix and show it in 'colorin' as "dng embedded matrix" and default to this (even if we have other matrices available).

Some sample EXIF:

Exif.Image.CalibrationIlluminant1 Short 1 17
Exif.Image.CalibrationIlluminant2 Short 1 21
Exif.Image.ColorMatrix1 SRational 9 8197/10000 -3931/10000 2593/10000 -2921/10000 9004/10000 4621/10000 -504/10000 832/10000 7365/10000
Exif.Image.ColorMatrix2 SRational 9 8235/10000 -2659/10000 -965/10000 -2426/10000 10625/10000 2078/10000 -686/10000 1246/10000 5898/10000

Associated revisions

Revision 5d4b53d9
Added by Tobias Ellinghaus over 6 years ago

Fix #8891: read the D65 Color Matrix from DNGs

History

#1 Updated by Pascal de Bruijn over 6 years ago

There may be cases where only a single matrix is present, in that case, we can ignore the CalibrationIlluminent tags.

#2 Updated by Tobias Ellinghaus over 6 years ago

  • % Done changed from 10 to 20
  • Priority changed from High to Medium
  • Status changed from Confirmed to Triaged

#3 Updated by Tobias Ellinghaus over 6 years ago

  • % Done changed from 20 to 100
  • Status changed from Triaged to Fixed

Applied in changeset darktable|commit:5d4b53d9d5e370b07655bc5dc517c112ef7c84e3.

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