CODEWITHSUNDEEP
pythonarraysnumpy
John
John

Reputation: 35

Create an extended view of a numpy array

I am learning image convolution and in order to handle the edges, I want to repeat the first and last rows/columns of the original array (at the center) like this :

1  1 2 3  3
1 [1 2 3] 3
4 [4 5 6] 6
7 [7 8 9] 9
7  7 8 9  9

(The values in the corners correspond to the diagonal elements.)

I will iterate over each pixel of the original array and use the array above to extract its 3x3 neighbors. So here is my question: is it possible to generate the view corresponding to this array so that I don't need to store a new (n+2)x(m+2) array in memory?

Upvotes: 1

Views: 81

Answers (1)

user2357112
user2357112

Reputation: 281663

There's no way to do this as a view, since there's no way to make the strides work. For a not-view solution, numpy.pad does the job. The signal-processing routines you're using might also let you specify a padding type.

Upvotes: 1

Related Questions