bug in transforms.py

[fenneishi]

🐛 Describe the bug

location:

vision/torchvision/transforms/transforms.py

Line 631 in 112accf

if h + 1 < th or w + 1 < tw:

fix:

if h + 1 < th or w + 1 < tw: ==>if h < th or w < tw:

cc @vfdev-5 @datumbox

[datumbox]

@fenneishi thanks for reporting.

@vfdev-5 I see this was introduced at #2816. For h=100, th=101 this will lead to 101<101 which seems wrong. Do you remember if there was a specific reason for adding the +1s or you think it's a bug?

[vfdev-5]

Yes, it is a bug. The condition if h + 1 < th or w + 1 < tw: was derived wrongly fromtorch.randint(0, h - th + 1, size=(1,)) as we need to generate a random int value. h - th + 1 is the upper non-inclusive boundary.

It should be h - th + 1 >= 2 -> h + 1 >= th + 2 -> h >= th + 1 or h > th. We also need to take into account that h == th. Thus, obviously correct condition is if h < th: raise error

[fenneishi]

thanks