divide an N*N array into square blocks (patches)

Question

Im pretty new to python. I have a np array (image) of size (128x128) and I want to divide it into 64 patches of 16x16. how can I slice the array? and How can I reassemble it into a 128x128 array afterwards?

I tried this but it's adding memory expense when I try to reassemble it

import numpy as np
xpx = np.random.rand(5,128,128)

new=np.zeros((5,64,16,16))


for i in range(0,5):
  w=0
  for j in range(0,128,16):
    for k in range(0,128,16):
      new[i,w]=xpx[i,j:j+16,k:k+16]
      w=w+1

What does "adding memory expense" mean? How did you measure that? How did you reassemble it? — mkrieger1, Dec 23 '22 at 08:24

score 0 · Answer 1 · answered Dec 23 '22 at 08:26

0

Split the array into 64 patches of size 16x16

patches = np.split(image, 64, axis=0)

Reassemble the patches back into a single array

reassembled = np.concatenate(patches, axis=0)

answered Dec 23 '22 at 08:26

kalzso

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divide an N*N array into square blocks (patches)

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