LabelSampler showing none, but Label has nonzero values

Hi all, I am facing a strange issue with LabelSampler. Here is the code for initialization of LabelSampler:

    sampler = torchio.data.LabelSampler(patch_size)
    patches_queue = torchio.Queue(subjects_dataset, max_length=q_max_length,
                                  samples_per_volume=q_samples_per_volume,
                                  sampler=sampler, num_workers=q_num_workers,
                                  shuffle_subjects=False, shuffle_patches=True, verbose=q_verbose)

For some images in my dataset, it throws the error:

RuntimeError: Empty probability map found: /path/to/mask/

But, when I have a look at these images, the mask is non-zero, but still this error is thrown. I am confused regarding this issue. Here is the link to the zip file for the case which is showing this error: https://drive.google.com/file/d/1kJ7DORGzZt8DXflS3bJz-Hj4gcWmrBe7/view?usp=sharing Please let me know if something is not clear. Thanks for your help! Megh

[fepegar]

No worries! Thanks again for reporting, it’s very helpful.

[meghbhalerao]

Hi @fepegar, Thanks so much for your detailed explanation, that makes sense! Thanks again, Megh