Allow full crop

[rctzeng]

Hi, I just found Augmentor. It is a great tool!
So, I extended a little bit to allow for a common operator - the full crop(i.e. cropping into size larger than the original size).
I hope this fix would be useful for other users, too.

[mdbloice]

Hi @Lubebul
thanks for the PR, that's something I wanted to add, however right now as it is we'd need to alter it a bit because within the do(image) function, there cannot be any randomness (this is for the ground truth, multi-image augmentation stuff, so that any images passed in pairs through the perform_operation() function are returned with the same alterations.

So the

left_shift = sign_w * random.randint(0, int(sign_w * diff_w))
down_shift = sign_h * random.randint(0, int(sign_h * diff_h))

stuff would need to be moved outside of do() somehow. I can do that myself, or do you wanna do that yourself and change your PR?
M.

[rctzeng]

@mdbloice, thanks for the comment.
I've moved the random shift from do() to perform_operation() following the approach in class CropPercentage.

[mdbloice]

@Lubebul, great thanks I will look at the code again and merge it as soon as I'm done taking a look.