Faster way to extract patches from images?

Question

I am trying to extract patches of fixed size centered at some given position (x,y). The code is given below-

for i,j in zip(indices[0],indices[1]):
    patch         


        

Answer 1

Using scikit-learn:

from sklearn.feature_extraction.image import extract_patches

all_patches = extract_patches(x, patch_size)

upper_left = indices - patch_size // 2
patches = all_patches[upper_left[0], upper_left[1]]

A similar function can be found in scikit-image: view_as_windows.