I divided a (512x512) 2-dimensional array to 2x2 blocks using this function.
skimage.util.view_as_blocks (arr_in, block_shape)
array([[ 0, 1, 2, 3],
[ 4, 5, 6, 7],
[ 8, 9, 10, 11],
[12, 13, 14, 15]])
>>> B = view_as_blocks(A, block_shape=(2, 2))
>>> B[0, 0]
array([[0, 1],
[4, 5]])
>>> B[0, 1]
array([[2, 3],
[6, 7]])
Now I need to put the same blocks to their original places after manipulation but I couldn't see any function in skimage for that.
What's the best way to merge the non-overlapping arrays as it was before?
Thank you!
Use transpose/swapaxes to swap the second and third axes and then reshape to have the last two axes merged -
B.transpose(0,2,1,3).reshape(-1,B.shape[1]*B.shape[3])
B.swapaxes(1,2).reshape(-1,B.shape[1]*B.shape[3])
Sample run -
In [41]: A
Out[41]:
array([[ 0, 1, 2, 3],
[ 4, 5, 6, 7],
[ 8, 9, 10, 11],
[12, 13, 14, 15]])
In [42]: B = view_as_blocks(A, block_shape=(2, 2))
In [43]: B
Out[43]:
array([[[[ 0, 1],
[ 4, 5]],
[[ 2, 3],
[ 6, 7]]],
[[[ 8, 9],
[12, 13]],
[[10, 11],
[14, 15]]]])
In [44]: B.transpose(0,2,1,3).reshape(-1,B.shape[1]*B.shape[3])
Out[44]:
array([[ 0, 1, 2, 3],
[ 4, 5, 6, 7],
[ 8, 9, 10, 11],
[12, 13, 14, 15]])