Replace an ad hoc 3x3 matrix, that was supposed to match LittleCMS matrix
but did not, with our new consistent weston_mat3f API.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
The primaries and the white point are the fundamental definition of the
color spaces in these tests. Instead of hard-coding mat2XYZ, use
LittleCMS to derive the result from the fundamental definition.
This removes derived hard-coded constants, which is a benefit in itself.
How these constants were originally produced was not mentioned in
0c5860fafb but I was able to reproduce
them with python3:
import colour
import numpy as np
x = colour.RGB_COLOURSPACES['sRGB']
w_d50 = np.array([0.34567, 0.35850])
print(x.chromatically_adapt(w_d50, 'D50', 'Bradford'))
It's identical to 3-4 decimals of the hardcoded values, and also for
Adobe RGB. I printed the LittleCMS generated values as well, and they
are the same as with python up to roughly 4 decimals.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
We'll need to craft ICC profiles in the CM&HDR protocol implementation
tests. So move it from color-icc-output-test.c to the LittleCMS helper
in our test suite.
This also removes some unused headers from color-icc-output-test.c, as
we've moved a bunch of code to the LittleCMS helper.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
This function sets some basic text tags to make an ICC file better
formed.
The code is taken from LittleCMS, https://github.com/mm2/Little-CMS.git
git revision
lcms2.13.1-28-g6ae2e99 (6ae2e99a3535417ca5c95b602eb61fdd29d294d0)
file src/cmsvirt.c.
Suggested-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This adds a new test helper library that depends on LittleCMS 2.
For starters, the library implements conversion from enum transfer_fn to
ICC multiProcessingElements compatible LittleCMS curve object.
That conversion allows encoding transfer funtions in ICC files and
LittleCMS pipelines with full float32 precision instead of forcing a
conversion to a 1D LUT which for power-type curves is surprisingly
imprecise.
This also adds CI tests to make sure the conversion matches our
hand-coded transfer functions.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
