PIL PNG IOError
hobu at IASTATE.EDU
Wed Mar 30 10:43:10 EST 2005
Try turning off interlacing in your OUTPUTFORMAT. I've had PIL choke on
interlaced PNGs before (depending on the PIL version).
At 09:41 AM 3/30/2005, Sean Gillies wrote:
>On Mar 29, 2005, at 3:58 PM, Adam Ryan wrote:
> > Hello to all,
> > I'm using Python Mapscript, ReportLab and PIL to generate PDF files on
> > Windows XP. I generate an image using mapscript, save it, and then
> > insert
> > it into my pdf 'canvas':
> > Canvas.drawInlineImage(myfile,x,y,w,h)
> > If my mapfile outputformat is gif, no problem - I get a nice pdf file.
> > But
> > if my outputformat is png, I get an IOError:
> > File "C:\python23\lib\site-packages\PIL\ImageFile.py", line 192, in
> > load
> > IOError: unknown error when reading image file
> > Your thinking I'm posting to the wrong listserv right? Well, if I take
> > that png file and open it up in Micro$oft Paint and then save it, my
> > routine then works without a problem. So I compared the two png files
> > (before and after saving with Paint) with gdalinfo but got identical
> > results. I did notice that there was a file size decrease after
> > saving.
> > But I don't know what else could be different about the files. Any
> > ideas?
> > Here are two examples of file size reduction with output format:
> > OUTPUTFORMAT
> > NAME png
> > DRIVER "GD/PNG"
> > MIMETYPE "image/png"
> > IMAGEMODE PC256
> > EXTENSION "png"
> > END
> > Reduction: 146kb to 137kb
> > outputformat
> > name "png"
> > driver "GD/PNG"
> > imagemode "RGB"
> > mimetype "image/png"
> > extension "png"
> > End
> > Reduction: 272kb to 205kb
> > Any sugestions would be grand. Cheers to all,
> > Adam
>Sorry, but I cannot reproduce this problem on Linux or on windows
>(Python 2.3.3 and PIL 1.1.5). PIL opens my mapscript PNG output just
>Can you remind me of the source of your MapServer/mapscript software?
>sgillies at frii dot com
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