On Wed, 10 Dec 2003, Toby Bartels wrote:
Diffing images is kinda hard. For vector image formats it's a little easier, and for stuff like SVG it might actually be practical, but for most purposes it's _extremely_ difficult to automatically detect the "difference" between two images. I doubt it would be worth the effort.
I was hoping that for SVG it would be practical and even useful, and if one is using SVG images, then maybe svgwiki already does this. But for PNGs and JPEGs? Ha! No, not worth the effort.
It is possible to diff bitmap images, as this is done with motion detection in security cameras. For example, I took a testsuite of SVG's from W3C and ran them through Sodipodi, then used the image differ to find where Sodipodi differed from the spec, using a tool called motiontrack: http://freshmeat.net/projects/motiontrack/
Bryce