how to rearrange each block into a column vector? [duplicate] - matlab

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Efficient Implementation of `im2col` and `col2im`
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Closed 7 years ago.
example: I have an image,it's size 512X512pixel,then i have splited it into 8x8 blocks.Now i would have 64x64 blocks.Now how to rearrange each block 8x8 into column vector so that the dimension would be 64x4096pixel without inbuilt function "im2col".please help me out.
Thanks.

x=rand(512,512);
xi=mat2cell(x,8*ones(1,64),8*ones(1,64));
xii=cellfun(#(x)reshape(x,1,64),xi,'UniformOutput',false);
y=cell2mat(xii);

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