Question about generate_spatial_bounding_box

[yiheng-wang-nv]

Hi, I just found that the generate_spatial_bounding_box may create invalid coordinates.
For example:

a = torch.zeros([1, 100, 100])
a[0, -1, -1] = 1

The output of generate_spatial_bounding_box(a) is:
([99, 99], [100, 100])

However, the valid coordinates of a is 0 to 99, and cannot be 100.

I think This line:

MONAI/monai/transforms/utils.py

Line 916 in 89f0bd4

max_d = arg_max[-1] + margin[di] + 1

may be we should not do +1.

Am I right?

[yiheng-wang-nv]

Hi @Nic-Ma , @wyli , what do you think?

[Nic-Ma]

Hi @yiheng-wang-nv ,

Thanks for your finding, I am not whether it's a bug, let me try to double-check ASAP.

[wyli]

I think that's the intended behaviour, the function computes the coordinates, and then we can index the array with a[:, 99:100, 99:100] (it returns tensor([[[1.]]]))

[Nic-Ma]

Hi @yiheng-wang-nv ,

I enhanced the doc-string for this question in another transform doc related PR: #3494.

Thanks.