I was working with the function (Python, Numpy, OpenCV3) over an image, and this is the sample output I have -

[[[539 340 897 538]]

 [[533 340 877 538]]

 [[280 460 346 410]]

 [[292 462 353 411]]

 [[540 343 798 492]]]

Its size is (5,1,4)

I am trying to understand what scenario will the function output something like (5,2,4) or (5,3,4). But I can't think of any and all the images I have worked with right now, it's a 3D array with the number of columns as 1.

Wouldn't just a 2D array be sufficient and perhaps more efficient?