> Report bugs to this list.
- A week or so ago, I reported that PIL loads multi-byte (e.g. 16-
and 32-bit raster data) TIFF files incorrectly if the files were
written as big-endian. (I also and provided a test case and patch.)
Now, I just discovered a minor problem in my patch relating to 32-bit
images, so I will send a new one in a few hours. This problem has
been in PIL for some time, and has basically disqualified it for use
in scientific imaging (which uses 16-bit data all of the time). I'd
love to get that changed.
- There is a buffer-overflow problem in 'struct
ImagingMemoryInstance' defined in 'Imaging.h'. Specifically, this
struct has a field defined as follows:
char mode[4+1]; /* Band names ("1", "L", "P", "RGB", "RGBA",
"CMYK") */
However, mode strings with more than 4 characters are copied into
this buffer via strcpy, clobbering other data fields in the struct. I
will provide a patch that makes the buffer large enough to hold all
mode strings that might be used, and changes the strcpy calls to a
strncpy. This patch also I will try to provide in a few hours.
- The 'fromarray' command is a bit broken in Image.py:
Specifically, the following stanza is incorrect --
if mode is None:
typestr = arr['typestr']
if not (typestr[0] == '|' or typestr[0] == _ENDIAN or
typestr[1:] not in ['u1', 'b1', 'i4', 'f4']):
raise TypeError("cannot handle data-type")
typestr = typestr[:2]
if typestr == 'i4':
...
The error is that 'typestr = typestr[:2]' should instead be 'typestr
= typestr[1:]'
- Also, the to/from array commands don't handle 16-bit images, though
it could be accomplished easily. I will provide a patch for this too.
- I still think that the handling of 16-bit images itself represents
a major bug (see my previous email to the list, but in short, having
to deal with big/little endian issues at the high-level API for 16-
bit images but no other image types is a bug and causes other bugs in
the code). I've been working on a patch to fix this, as described in
that earlier email. Probably this patch is too big a change to apply
to this release, but I would REALLY like to talk to someone about the
chances for 1.7 (or whatever) accepting changes that make 16-bit
image handling less vexing.
Thanks,
Zach Pincus
Program in Biomedical Informatics and Department of Biochemistry
Stanford University School of Medicine
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