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From: ImageAnalyst <imageanalyst@mailinator.com>
Newsgroups: comp.soft-sys.matlab
Subject: Re: divide 1280-by-960 image into 9-by-9
Date: Sat, 28 May 2011 15:44:50 -0700 (PDT)
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On May 28, 3:52 pm, "Roger Stafford"
<ellieandrogerxy...@mindspring.com.invalid> wrote:
>   To ImageAnalyst and Areeba: I just ran across a matlab function which computes a normalized cross correlation of two-dimensional arrays.  It is called 'normxcorr2' and is to be found in the Image Processing Toolbox.  The documentation can be read at:
>
>  http://www.mathworks.com/help/toolbox/images/ref/normxcorr2.html

> Roger Stafford

-------------------------------------------------------------
Yes, you're right.  Good find!  That will be handy to know.  I never
noticed it because it's not a "See Also" under xcorr2, possibly
because they're in different toolboxes (Signal vs. Image).  But when
you type "correlation" into the help, the normxcorr2 function doesn't
show up until the 9th one down (R2011a), and it's not even mentioned
at all when you go to the top entry on correlation.

There is actually quite a nice demo using it in there: "Registering an
Image Using Normalized Cross-Correlation" which does what I think
areeba wants to do in early explorations.  However I very much agree
with Roger that this method ultimately will not be very good at
detecting cancerous locations.  It may work for a few locations where
the cancer pretty much exactly looks like the template, but won't be
robust enough in general to be a useful algorithm in the real-world
practical sense.  However, if it's just for limited demo purposes,
like a student homework project, then it may fit the bill as long as
you list potential disadvantages and limitations of it in the
conclusions/summary.