id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
24948	BMP Image File treated as invalid	jerzyk	Andriy Sokolovskiy	"when assigning a .bmp (windows bitmap) image to an ImageField field, django reports error, responsible line, that raises an error is django/forms/fields.py:695 (to_python)

{{{
f.content_type = Image.MIME[image.format]
}}}

file is validated properly (opened, validated) and at the and, it's mime_type is detected by using a dictionary `Image.MIME`.

This dictionary is not documented and does not contain entries for BMP file, so it may be assumed that Django is using it's private api.

There are two options - push on Pillow to make this public API and fix an issue or use different method to find mime-type (e.g. python's standard mimetypes library)
"	Bug	closed	Forms	1.8	Release blocker	fixed	bmp, image		Ready for checkin	1	0	0	0	0	0