[Image-SIG] RMS difference patch

[Douglas Bagnall]

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