1 How should we handle incomplete files?
2 ======================================
4 Reading an incomplete TIFF sets i_incomplete, but no others do.
6 Should this only occur if a flag is set?
8 Should there be some indication of how much was read?
10 Some formats, like compressed BMP don't really have a way to tell. A
11 valid BMP might be 100 x 100 and only set 1 pixel in the data. Though
12 we can't tell what the non-set pixels should be in this case.