I have a patch that adds an RMS Difference method to the PIL.
Let me know if there is any interest in this. I originally wrote this to
help implement a video stabilization filter. You could also use
this to quantify how much a lossy compression algorithm distorts
an image relative to some other
I wrote:
2 ** (31-20) ** 0.5
9.9633077752473778
A pixel difference of 10 across the 1 megapixel image will wrap the sum
and crash.
But now I've read it and it looks like it should have been
(2 ** (31-20)) ** 0.5
45.254833995939045
So, not so bad, but nonetheless a problem.
douglas
