diff --git a/.gitignore b/.gitignore index 252aa91d4..ee76df517 100644 --- a/.gitignore +++ b/.gitignore @@ -113,3 +113,4 @@ ENV/ *.model +!documentation/assets/scribble_example.png \ No newline at end of file diff --git a/documentation/assets/scribble_example.png b/documentation/assets/scribble_example.png new file mode 100644 index 000000000..62e775cfd Binary files /dev/null and b/documentation/assets/scribble_example.png differ diff --git a/documentation/ignore_label.md b/documentation/ignore_label.md new file mode 100644 index 000000000..17336bba4 --- /dev/null +++ b/documentation/ignore_label.md @@ -0,0 +1,91 @@ +# Ignore Label + +The _ignore label_ can be used to mark regions that should be ignored by nnU-Net. When the _ignore label_ is used nnU-Net switches internally to a partial variant of its loss function (See our [paper](https://arxiv.org/abs/2403.12834) for more information). Consequently, all pixels marked with the ignore label are ignored during the loss computation and gradients are not propagated from these pixels. Furthermore, these pixels will also be excluded from model evaluation. The most common use-cases for the ignore label are: + +- Sparse annotation + - Annotation of all or a subset of slices with scribbles (Scribble Supervision) + - Dense annotation of a subset of slices + - Dense annotation of chosen patches/cubes within an image +- Coarsly masking out faulty segmentations in the reference segmentations +- Masking areas for other reasons + +If you are using nnU-Net's ignore label, please cite the following paper in addition to the original nnU-net paper: + +``` +Gotkowski, K., Lüth, C., Jäger, P. F., Ziegler, S., Krämer, L., Denner, S., Xiao, S., Disch, N., H., K., & Isensee, F. (2024). Embarrassingly Simple Scribble Supervision for 3D Medical Segmentation. ArXiv. /abs/2403.12834 +``` + +## Usecases + +### Scribble Supervision + +Scribbles are free-form drawings to coarsly annotate an image. As we have demonstrated in our recent [paper](https://arxiv.org/abs/2403.12834), nnU-Net's partial loss implementation enables state-of-the-art learning from partially annotated data and even surpasses many purpose-built methods for learning from scribbles. As a starting point, for each image slice and each class (including background), an interior and a border scribble should be generated: + +- Interior Scribble: A scribble placed randomly within the class interior of a class instance +- Border Scribble: A scribble roughly delineating a small part of the class border of a class instance + +An example of such scribble annotations is depicted in Figure 1 and an animation in Animation 1. +Depending on the availability of data and their variability it is also possible to only annotated a subset of selected slices. + +
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