The function `imcrop_tosquare` in session-0 has a minor problem

[vibertthio]

...
            crop = img[max(0, extra // 2 + 1):min(-1, -(extra // 2)), :]
...

The result will not be a square when extra is 1. For example, the crop is img[1:-1, :] when extra is 1.

It should be:

...
            crop = img[extra // 2:-(extra // 2) - 1, :]
...