Why using 'F.grid_sample()' in class RandomShiftsAug?

[Guozheng-Ma]

Actually, for the random shift operation, we can easily choose two random variable as the shift axis like this:

assert origin_image.shape=(512,3,84,84)
assert pad_image.shape=(512,3,92,92)
shift_x = random.randint(0,92-84-1)
shift_y = random.randint(0,92-84-1)
aug_image = pad_image[:,:,x:x+84,y:y+84]

Then we can get the augmented image.

I guess interpolation is the reason you guys choose F.grid_sample()?