[Image-SIG] A Pil Doubt

[Douglas Bagnall]

Carlos Moreira asks:

> Hi,
> 
>      I need some help. How I can, in Python Imaging Library, create a
> transparent GIF?


tsk,tsk.. it's illegal you know. 
I managed it by using a modifed version of the _save_netpbm function in 
/PIL/GifImagePlugin.py, which uses the external but common and free 
netpbm library.

I only wanted white as a transparent colour, so I hard-coded in the 
'#FFFFFF'. Everything except " -transparent '#FFFFFF' " is straight out 
of PIL.

douglas


def _save_netpbm_trans(im, fp, filename):
    import os
    file = im._dump()
    if im.mode != "RGB":
        os.system("ppmtogif -transparent '#FFFFFF' %s >%s" % (file, filename))
    else:
        os.system("ppmquant 256 %s | ppmtogif -transparent '#FFFFFF' >%s" % (file, filename))
    try: os.unlink(file)
    except: pass

Image.register_save("GIF", _save_netpbm_trans)   #sets PIL to use proper GIF compression
 







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