i have divided the image into blocks now, i want to access each block individually and i compute histogram how do i access each block

a=imread(img);
subplot(4,3,2)
imshow(img)
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0.05 1 0.95]);
[r, c, numOfBands] = size(a);
%dividing image into 8x8 subblocks
bs=8;%block size
nob=(r/bs)*(c/bs);%Total no of blocks
k=0;
for i=1:(r/bs)
    for j=1:(c/bs)
        Block(:,:,k+j)=a((bs*(i-1)+1:bs*(i-1)+bs),(bs*(j-1)+1:bs*(j-1)+bs));
    end
    k=k+(r/bs);
end

[Jan]

Please read an apply http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

Answer 1

[Image Analyst]

You have the block so just pass it into histogram()

h = histogram(Block(:,:,k+j));

[teja jayavarapu]

I want to compare each block to every other block in the database so, how should I do that

[Walter Roberson]

Given the histograms for two different blocks, how do you want to "compare" them ?

[teja jayavarapu]

I am dealing with content based image retrieval in this,I am using color feature to extract the matchsdimages from the database.so I am using the method of local color histogram.so I want to compare each block of image to every block in the database

[Image Analyst]

Please define compare mathematically. Do you mean the delta E (color difference), the MSE in RGB space, or what?

[teja jayavarapu]

I know how to compare , but after diving image into blocks (suppose 32 blocks) how to acces each block block of an image to compare with respective block in the database(loaded with images)