Fix the range of offset in random_crop

[akitotakeki]

No description provided.

[Hakuyume]

Thank you for PR. How about using random.randint (https://docs.python.org/3/library/random.html#random.randint)? It returns an integer from [a, b] (both boundaries are included).

And I find that img.shape[1] == H and img.shape[1] > H can be merged.

    if img.shape[1] >= H:
         y_offset = random.randint(0, img.shape[1] - H)
    else:
         raise ValueError(...

[akitotakeki]

@Hakuyume Thanks for the review. I've fixed the points.

[Hakuyume]

LGTM