Replace Python-generated test TIFFs with libtiff-generated ones to
eliminate circular validation. The C program (gen_seq_tiff.c) uses
libtiff's TIFFWriteScanline with MSB-first packed bit streams.
Cross-validated: tifffile independently confirms all 27 images match
the original Python-generated versions byte-for-byte. tiffinfo validates
all IFD structures. All 27 image-tiff decode tests pass unchanged.
The test files in this directory mostly have dimension 157x151.
The naming convention is
photometric-channels-bits.tiff
minisblack-1c-16b.tiff
minisblack-1c-8b.tiff
miniswhite-1c-1b.tiff
palette-1c-1b.tiff
palette-1c-4b.tiff
palette-1c-8b.tiff
rgb-3c-16b.tiff
rgb-3c-8b.tiff
logluv-3c-16b.tiff: logluv compression/photometric interp
minisblack-2c-8b-alpha.tiff: grey+alpha
BMP files (anchient BMPv2 since v3 does not work):
palette-1c-8b.bmp
rgb-3c-8b.bmp
GIF files (anchient GIF '87 since modern GIF does not work):
palette-1c-8b.gif
PNM files:
minisblack-1c-8b.pgm
miniswhite-1c-1b.pbm
rgb-3c-8b.ppm