Re: [Dvipng] accessing alpha channel

[Jan-Åke Larsson]

Bob McElrath wrote:
> I use the following sequence of commands using python's Imaging library:
>
>     im = Image.open(os.path.join(workingDir, imname))
>     im2 = Image.new('RGBA', (im.size[0], im.size[1]), (255,255,255))
>     im2.paste(im, (0, 0))
>
> To explicitly create an alpha channel I use:
>     alpha = ImageChops.invert(im.convert('L'))
>     im = im.putalpha(alpha)
>
> This creates a PNG with a proper alpha channel.  I would VERY much like
> it if dvipng did this for me.  I would love it if you could hack it in
> to dvipng.

Unless I am mistaken, the CVS version of dvipng does create a
proper-alpha PNG if you use '-bg Transparent' (capital T). This is to be
released very soon as dvipng-1.6. Please try it out, I'd like to remove
any remaining flaws.

/JÅ