slices = mat2cell(MosaicArray, 64 * ones(1,size(MosaicArray,1)/64), 64 * ones(1,size(MosaicArray,2)/64) );
Now you would need to get rid of 4 of the items, but at the moment I do not know which 4 are the empty ones and I do not know whether the unraveling should be along the rows or down the columns. Probably it should be
slices = transpose(slices); %rows become priority
slices(61:end) = []; %remove the 4 empty slices
