Split a matrix into smaller sub matricies

I've seen this answered on the web many times but none of the answers seem to give me what I need, so here it goes...

As a simple example, I have a 100x100 matrix

if true
x = ones(100)
  % code
end

I would like to split this into 100 sub matrices, of size 10x10.

I would then like to sum each element of each sub matrix to give me a 10x10 matrix of these sums.

I am using these Matrices I quiver3 after this so I cannot use the mat2cell (as far as I understand) function to manipulate them into sizes I want.

Any suggestions appreciated, as always, thanks in advance for your help. John.

[Fangjun Jiang]

What is the specification of the split, evenly split the row and column into 10, like 1 to 10, 11 to 20, ..., 91 to 100?

Answer 1

[Matt J]

Using SEPBLOCKFUN ( Download )

   result = sepblockfun(yourMatrix, [10,10], 'sum');

[John Draper]

Yes this works but it gives me the wrong answer. I think the problem lies elsewhere. Thank you though.

Answer 2

[Image Analyst]

What are your complaints about both of the two methods in the FAQ: http://matlab.wikia.com/wiki/FAQ#How_do_I_split_an_image_into_non-overlapping_blocks.3F ?

[John Draper]

Sorry, which methods are you referring to?

Answer 3

[Image Analyst]

You can use blockproc() if you have the Image Processing Toolbox, both to split up the image and take the mean of each block:

meanFilterFunction = @(theBlockStructure) mean2(theBlockStructure.data(:));
blockSize = [10, 10];
blockyImage = blockproc(grayImage, blockSize, meanFilterFunction);

See attach demo script below the image for a full demo.