Re: PNG image files with alpha channel

[Chong Yidong]

Miles Bader <address@hidden> writes:

> So the problem may in fact be something with the libpng 16-to-8-bit
> conversion code...

I found the error.  When setting the background color, we must provide
it in the original bit-depth of the image, even if we call
png_set_strip_16.  So, for 16-bit png images, it's just a matter of
supplying the background color at a 16-bit depth.

I've checked in a fix.