I'm afraid you need to rebuild the _imaging module; the patch touches libImaging/Unpack.c too (without that, you can only read big-endian 48-bit RGB files; that is, files that start with MM instead of II).
</F> On Sun, Apr 25, 2010 at 5:53 PM, Dan Blacker <dan.blac...@googlemail.com>wrote: > Hi Fredrik, > > Thanks for taking a look at this, I have downloaded the latest PIL source > and installed it, and replaced the TiffImagePlugin.py that was in pyShared > with the latest one. > > When running my script, I no longer get errors when reading my 16-bit tiff > file in. > > I do however now get an error when I try and convert and make a grayscale > copy of my file, in the middle of my script. (this should be 8bit): > > * File "16bittest.py", line 147, in <module> > im1 = im0.convert ("L", dither=Image.NONE) > File "/usr/lib/python2.6/dist-packages/PIL/Image.py", line 654, in > convert > self.load() > File "/usr/lib/python2.6/dist-packages/PIL/ImageFile.py", line 180, in > load > d = Image._getdecoder(self.mode, d, a, self.decoderconfig) > File "/usr/lib/python2.6/dist-packages/PIL/Image.py", line 374, in > _getdecoder > return apply(decoder, (mode,) + args + extra) > ValueError: unknown raw mode* > > Am I missing a value to pass into convert() to tell it to make an 8bit > file? > > Thanks, > > > > On 25 April 2010 13:48, Fredrik Lundh <fred...@pythonware.com> wrote: > >> Oops, that patch was broken, due to pilot error. Here's an incremental >> fix: >> >> http://hg.effbot.org/pil-2009-raclette/changeset/c3fb89aa181e >> >> Alternatively, just grab the latest PIL/TiffImagePlugin.py and >> libImaging/Unpack.c and drop them on top of the existing versions. >> >> </F> >> >> On Sun, Apr 25, 2010 at 1:07 PM, Fredrik Lundh <fred...@pythonware.com> >> wrote: >> > This isn't really a full solution, but the following patch at least >> > allows PIL to read 3x16-bit RGB TIFF files, converting them on the fly >> > to 24-bit RGB. Note that it requires new binaries to handle little >> > endian (intel) files: >> > >> > http://hg.effbot.org/pil-2009-raclette/changeset/45c2debe0fc3 >> > >> > Unfortunately, your sample use "contiguous" pixel storage, which makes >> > the descriptor manipulation tricks I mentioned harder to implement >> > efficiently for PIL 1.1.7. I played a bit with libtiff's tiffcp >> > utility to see if that could be used as a preprocessor (which is >> > otherwise a great way to handle more "obscure" TIFF flavours), but at >> > least the version I have doesn't handle 16-bit images well either. I >> > need to think a bit more about this, I think... >> > >> > </F> >> > >> > On Thu, Apr 22, 2010 at 10:57 PM, Fredrik Lundh <fred...@pythonware.com> >> wrote: >> >> Oh, missed that there was one in your first post. I'm a bit busy >> >> right now, but I'll take a look when I find some spare time. >> >> >> >> </F> >> >> >> >> On Thu, Apr 22, 2010 at 10:56 PM, Fredrik Lundh < >> fred...@pythonware.com> wrote: >> >>> On Tue, Apr 13, 2010 at 10:52 AM, Dan Blacker >> >>> <dan.blac...@googlemail.com> wrote: >> >>>> Hey guys, >> >>>> >> >>>> Thanks for your input, >> >>>> >> >>>> The image is only of a tiny cropped area of a long strip of color >> kodachrome >> >>>> film - I will send a better example with some more color in it when I >> get a >> >>>> chance. >> >>>> >> >>>> I was under the impression that PIL handled 16 bit images >> (experimentally) >> >>>> but does this only apply to 16-bit grayscale images? >> >>>> >> >>>> Am I going up a dead end trying to read my images with PIL? >> >>> >> >>> The current PIL release only supports 8 and 32-bit/pixel internal >> >>> storage; that's enough to hold e.g. RGB triplets or 32-bit signed >> >>> integers, but not 3x16 bit pixels. I'd love to support more storage >> >>> formats (machines are a lot bigger now than when the internal, >> >>> intentionally very simple storage model was designed) including HDR >> >>> formats (float16 etc), but rearchitecting the internals without >> >>> breaking all existing code is a pretty big project... >> >>> >> >>> There is some limited support for 16-bit storage, by packing two >> >>> pixels per 32-bit storage unit, but not all operations support this >> >>> (it's mainly intended to support working with huge, memory mapped >> >>> single-layer images, such as satellite data). >> >>> >> >>> There are some non-standard tricks that may help you with your >> >>> specific case, though. All codecs do things in two steps; the first >> >>> is to identify the file format and build a descriptor of where the >> >>> image data is in the file (the "tile" map). The second step then >> >>> loads pixel data on demand, using that descriptor. You might be able >> >>> to tweak the descriptor before loading the image, to load one layer at >> >>> a time. Do you have any samples? >> >>> >> >>> </F> >> >>> >> >> >> > >> > >
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