divide an image into blocks

How can I divide an image into a specific number of blocks, stir them and get a new messy image?

Answer 1

[Matt J]

Using mat2tiles,

https://www.mathworks.com/matlabcentral/fileexchange/35085-mat2tiles-divide-array-into-equal-sized-sub-arrays

it is very easy:

initialImage=imread('sherlock.jpg');

blocksize=[40,40,inf]; %must divide evenly into size(initialImage)

C=mat2tiles(initialImage,blocksize);

C(:)=C(randperm(numel(C)));

messyImage=cell2mat(C);

        figure;
        subplot(1,2,1);
        imshow(initialImage);
        subplot(1,2,2)
        imshow(messyImage)