I'll continue testing with all bitdepths. I only tested 8bit, 24bit and 32bit so far.
Thanks for the information. If you find any other issues with loading or saving please message me and I will try to verify it and correct the issue.
I made two small changes to the original load function to allow loading 32bit bmp images. One involved the colormap the other added pixel format and alignwidth, alignbytes to load 32bit bmp's. The rest is as it was. It was written by someone else whose name appears in the source code. I haven't tested all of it.
The AROS picture datatypes have been in a sad state for a long time, many missing save functions. I hope to fix as much as I can but there may be room for improvement on that.
Did you test the original bmp datatype to find if it can load 1bit and 4bit correctly? I haven't.