Creates a black border around an image. 5 at the top 10 at the left 15 at the bottom 20 at the right The original image surrounded by zero padding, which usually means black pixels. top padding and left padding. defaults to (1 1). bottom and right padding. defaults to (1 1). there may be a third element in the list but... there may be a third element in the list but it must be 0 and it's only allowed when there are three dimensions in the input grid. it is reserved for future use.