Similarity between two matrices of different sizes

Dear all,

I have two matrices(or images) of different sizes. Now i want to compare these two matrices and find out the maximum similarity between the matrices. The output should contain the points of similarity between them. Is these any way to do it in matlab using any function or toolbox or kindly some way to write the code ..

Thank you Gurunath

Answer 1

[Dustin]

I assume that by similarity you are referring to elements having the same values in the same locations. In that case, I suggest subtracting the two matrices, and finding the elements which are zero. I doubt that this approach will help you find similar regions in images though.

Answer 2

[Paulo Silva]

%two random arrays with variable size and data
a=randi([1 10],randi([1 10]),randi([1 10]));
b=randi([1 10],randi([1 10]),randi([1 10]));
%find the common dimensions
mxr=min(size(a,1),size(b,1))
mxc=min(size(a,2),size(b,2))
%compare the values
a(1:mxr,1:mxc)==b(1:mxr,1:mxc)

you get the answer in one array with logic values, 1 when the values at same index are equal and 0 if they are not equal

Answer 3

[Walter Roberson]

See this tutorial: http://www.mathworks.com/products/demos/image/cross_correlation/imreg.html

[Gayathri Nayar]

Sir, this link doesn't work anymore.