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>
These helpers allow collecting color difference statistics easily.
To be used in color-shaper-matrix-test.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
When defining a color space with a transfer function, this looks up the
inverse transfer function without needing to store that separately.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This will be useful to make a curve in a color pipeline pass-through
without needing to special-case skipping the curve.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Make process_pixel_using_pipeline() slightly easier to read by
extracting a meaningful function.
Pure refactoring, no behavioral changes.
Compared to previous, flip the scalar multiplication around, so that it
matches the mathematical order of matrix-vector multiplication.
Also document the layout conventions for lcmsVEC3 and lcmsMAT3. These
follow the convention used in LittleCMS for cmsVEC3 and cmsMAT3, and are
necessary to understand to review the matrix-vector multiplication for
correctness.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Looks like this was forgotten, and I managed to get compiler errors
about redeclaring all enums.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Individual struct fields are inconvenient to index into, yet most
operations on a color just repeat the same for each of RGB channel.
Being able to index into RGB avoids repeating the same code for each
channel.
Alpha channel is left as separate, since it is almost never handled the
same as RGB.
The union keeps the old .r, .g and .b addressing working. The static
asserts ensure the aliasing is correct.
For demonstration, two simple functions in color_util.c are converted.
Unfortunately initializers need to be corrected everywhere. Field .a is
not explicitly initialized because it is unused in these cases.
This change should make code easier to read.
This change requires gnu99 or c11 standard. gnu99 is already the default
in top-level meson.build.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
No functional change. Moved color processing
functions into shared files which can be used
between different tests.
Signed-off-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Pekka Paalanen