Very strange, when I try converting the same bitmap I get a C file with only 0xFF bytes in the bitmap array…
Try the option CF_INDEXED_1_BIT instead, I am currently unable to test this myself but the resulting array looks more promising already. I have attached the file below.
LaetitiaBats_index.c (13.2 KB)
EDIT: After looking at it again, I realised these weren’t 1-bit colors at all. My last option now that I can recommend is trying CF_TRUE_COLOR. This will generate an array with only 0xFF and 0x00, which seems to be more correct.