[svlug] compare image

[Prasanth A. Kumar]

Karen Shaeffer <shaeffer at best.com> writes:
<snip>
> Hi Karsten,
> 
> Yes, this is a basic premise of the generalized mathematics
> of image and video compression. (e.g., JPEG or MPEG) An excellent
> general reference is:
> 
> Arun N. Netravali and Barry G. Haskell; Digital Pictures: Representation
> and Compression; Plenum Press, 1988 ATT Bell Labs
> 
> There is a second edition in print.
> 
> If you look into these mathematics, you'll realize one must be clear
> about defining what is meant by *difference*. It's all about thresholds
> and difference algorithms. By difference one might mean average values
> for luminance or some windowed metric, etc. More likely, Will is most
> interested in detecting changes in image objects. In that case, the
> mathematics must detect temporal variances in edges. Here edges are
> defined as contiguous lines of high contrast.
> 
> As Will suggested, this genre of application *ought* to exist. If not,
> I'm sure someone will have a wonderful time writing it. This is all
> very interesting stuff--interesting algorithms and mathematics.
<snip>

Couldn't one just convert the two images into rgb format, then subtract
respective pixels of each color channel and then get the
root-mean-square value. The closer the value is towards zero, the more
similar the image. It is very crude technique but is worth trying.

-- 
Prasanth Kumar
kumar1 at home.com