Added cLUT profile creation to validate linearization algorithm
for DToB3 tag (direction dev to PCS). The 3DLUT is
built by using raw matrix conversion from dev to XYZ and reverse
(XYZ to device).
The test uses floating point pipeline, known as unbounded mode of LCMS.
The details are described in ICCSpecRevision_02_11_06_Float.pdf
The purpose of these new test cases is to keep the GL-renderer 3D LUT
path tested even after color-lcms and GL-renderer start using
specialized matrix-shaper paths.
These also exercise build_eotf_from_clut_profile() in color-lcms, but do
not actually verify it. These cases only test that the recovered EOTF
and its inverse produce an identity mapping together.
BT.2020 is not used in these tests, because the RGB-XYZ conversion
matrix does not stay inside [0.0, 1.0] in either direction, which would
be a problem for the 3D LUT element in the multiProcessingElement
pipelines. Handling that would have been possible, but testing with
AdobeRGB color space should suffice while keeping the test code from
being even more complicated.
roundtrip_verification() tests that we succeed in creating cms
pipelines correctly in both directions so that the resulting ICC file is
better behaved. The Weston test itself only cares about the BToD
direction.
Credits to:
Vladimir Lachine <vladimir.lachine@amd.com>
Graeme Gill <graeme@argyllcms.com>
Co-authored-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Signed-off-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Vitaly Prosyak