Imread doesn't read PGM Image

[berak]

ppm images have a text header. can you show yours ?

i dont think, the pxm importer handles 16bit properly

opencv/opencv/blob/a1e4444fb5ce9ee3d4afa80073e49dcc7ed6c6dd/modules/imgcodecs/src/grfmt_pxm.cpp#L159-L165

any chance, you can debug this ?

that said, ppm is the most simple image format ever.
c++ ifstream, 20 lines of code or so …