The tests cover issue #117 and pull request #118, extending the coverage
for all color types that may have tRNS chunks:
- color type 0 (grayscale), the tRNS chunk contains a single gray level
- color type 2 (truecolor), the tRNS chunk contains a single RGB color
- color type 3 (indexed color), the tRNS chunk contains a series of
one-byte alpha values
Add sample PNG files from the "official" test-suite for PNG
created by Willem van Schaik.
Add <define>BOOST_GIL_IO_TEST_ALLOW_READING_IMAGES to Jamfile for PNG tests.
NOTE: Deliberately not defined BOOST_GIL_IO_TEST_ALLOW_WRITING_IMAGES
as it seems to require some extra configuration, currently it causes
some tests to fail. So, Jamfile likely needs more updates and clean-up.
Closes#120
