Find Correraltion coefficient of two adjacent pixels

I have 2 grayscale or color images. I want to find the histogram for the correlation of adjacent pixels of these 2 images(horizontally and vertically) using Histogram.

How can I choose n pairs of pixels. Let Images be I1 I2.

Also need to find MSE, 2-d Correlation coefficient & covariance.

Also what is CROSS-CORRELATION

Thanks

Answer 1

[Walter Roberson]

What did your country's version of Google reply with when you gave it the query,

Also what is CROSS-CORRELATION

??

[LOKESH]

Hello sir.Leave the Cross correlation.

Any solution for finding correlation coeffecient[for horizontal direction of adjacent pixels]

Answer 2

[Image Analyst]

Perhaps you're really thinking of the gray level cooccurrence matrix??? That is performed by graycomatrix() in the Image Processing Toolbox. Because with a histogram, you lose all knowledge of whether a graylevel (belonging to a particular pixel) was next to another gray level. The histogram has no clue where the gray levels came from but graycomatrix does.

[LOKESH]

I am unable to get the graycomatrix() basics. I want to have the CORRELATION COEFFICIENT for horizontal direction of adjacent pixels.

This gives me a Histogram having 2 axes[(x,y), (x+1,y)], which displays values of pixels.

See at: http://www.freeimagehosting.net/wn2f5

http://www.freeimagehosting.net/nnbsy

Answer 3

[Ali Broumandnia]

 function  r_xy=AdjancyCorrPixel( P )
%UNTITLED3 Summary of this function goes here
%   Detailed explanation goes here
x1 = double(P(:,1:end-1));
y1 = double(P(:,2:end));
randIndex1 = randperm(numel(x1));
randIndex1 = randIndex1(1:3000);
x = x1(randIndex1);
y = y1(randIndex1);
r_xy = corrcoef(x,y);
scatter(x,y);
xlabel('Pixel gray value on location (x,y)')
ylabel('Pixel gray value on location (x+1,y)')
end