[Image-SIG] Question on TIFF EXTRASAMPLES tag support

[Chris Cogdon]

On Wednesday, Sep 10, 2003, at 12:06 US/Pacific, Tom Bridgman wrote:

> We're using PIL for converting TIFFs generated by our animations into
> additional products for web and video release.  Today I encountered an
> incompatible/unsupported TIFF format generated in one of our newer
> processes.  Setting the Image.DEBUG flag, I found that the file had:
>
> format key: (2, 1, (8, 8, 8, 8), (1,))
> - unsupported format
>
> while apparently the nearest supported formats listed in
> TiffImagePlugin.py are
>
>     (2, 1, (8,8,8,8), (0,)): ("RGBX", "RGBX"),
>     (2, 1, (8,8,8,8), (2,)): ("RGBA", "RGBA"),
>
> Apparently, this file has an incompatible 'EXTRASAMPLES'=1 flag but 
> this
> appears to be indicating the presence of an alpha channel.
>
> After checking some additional references, I'm wondering what's the
> difference between the EXTRASAMPLES=1 and RGBA?  If there is no
> significant difference, couldn't support for this format be installed 
> by
> just adding:
>
>     (2, 1, (8,8,8,8), (1,)): ("RGBA", "RGBA"),
>
> to the OPEN_INFO list in TiffImagePlugin.py?
>
> Can anyone enlighten me?
>
> Should this be installed in the distribution?
>
> Other comments/suggestions?  I'm no expert on PIL - I'm making this
> determination based on one afternoon of study...

Try adding that in yourself... does it still work, and work with your 
image type as expected? :)


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