def read(cls, fp, **kwargs):
kind = SectionDivider(read_fmt('I', fp)[0])
signature, key = None, None
if is_readable(fp, 8):
signature = read_fmt('4s', fp)[0]
assert signature == b'8BIM', 'Invalid signature %r' % signature
key = BlendMode(read_fmt('4s', fp)[0])
sub_type = None
if is_readable(fp, 4):
sub_type = read_fmt('I', fp)[0]
return cls(kind, signature=signature, key=key, sub_type=sub_type)
