MATLAB: Binning regions of a 2D matrix slices (and extending this into the third dimension)

Question

Hello,

I am having an issue binning regions of a 3D matrix (but I want the binning to occur in the X-Y dimension for each Z slice). Let's say I have a matrix of 512x128x1200, each 2D slice has dimension 512×128, but say I want to bin the pixel counts such that we create a 2D sliced 32×32 matrix (each element being the sum of 16×4 regions within the original larger matrix, is this possible? Then if we can perform this binning in 2D I want to extend this to each element in the Z-direction

It also would be nice then in future to have control of the X/Y bin 'width' so that the matrix can be reshaped into other square orientations, I have just chosen 32×32 as an arbritary starting point!

Hopefully that makes sense!

Cheers

Answer 1

This assumes the first/second dimensions of your matrix are divisible by 32

% Test matrix
A=rand(512,128,1200);
binsz = 32;
[m,n,p] = size(A);
mr = m/binsz;
nr = n/binsz;
B = reshape(A,mr,binsz,nr,binsz,p);
B = sum(B,[1 3]);
B = reshape(B,binsz,binsz,p);