Label image sampler

[tobiashepp]

Hi fernando,

I recently switched from tf to pytorch and I was really happy to find your library.
Great work! Thanks.

• I added a more efficient image sampler to sample random patches which should contain
  at least one point of a specific label.
  https://github.com/lab-midas/midas-torchio/blob/dev_tobias/torchio/data/sampler/label.py
  (code and examples are still a bit messy, I will work on this the next days).
  But maybe you can use (parts of) it ;)

• There was also a minor issue if the patch size is equal to the image size in a dimension
  (missing +1, rand numbers low=a high=b -> sample from [a,b) so b can be the max_size). I corrected this.
  This is very helpful to use the patch sampler as a slice sampler (for instance slicing 512x512 from 512x512x156 volumes).

Cheers
Tobias

[fepegar]

Hi @tobiashepp

That's great! I'm glad you're finding it useful. Please don't hesitate to post more feedback or issues here.

It would be amazing to include your sampler here if you think it's worth it. You can create a PR whenever you're ready and I'll review it.

Someone told me about that bug when the patch size is the same as the image. I'll create an issue. Thanks for reporting!

[fepegar]

FYI I've started working on more efficient samplers in #175.