[Image-SIG] Re: A question about PIL attributes

[Fredrik Lundh]

"Matt G" wrote:

> Hi.  I'm using the Python Image Library  to do some image manipulations.  I like that the PIL
> objects have attributes like format, size, info (dictionary) etc.  My problem is...when I
> apply some filter, say ImageChops.invert, or Image.transpose, it looses
> the addributes.  For example
>
> if DEBUG: print "Before transpose, format is: " + str(pil.format)
> pil = pil.transpose(Image.FLIP_LEFT_RIGHT)
> if DEBUG: print "After transpose, format is: " + str(pil.format)
>
> the first output prints "JPEG" or "GIF" or whatever.
>
> after the transpose, the output is "None"

the "format" attribute is only set on image objects that are
read directly from a file; once you start processing the image,
the format is no longer defined.

if you need to keep track of the original format, just copy the
attribute to a separate variable:

    format = pil.format
    pil = pil.transport(...)
    ...
    pil.save(outfile, format=format)

</F>