TopoMortar: A Dataset to Evaluate Topology Accuracy in Image Segmentation


Juan Miguel Valverde (Technical University of Denmark), Motoya Koga (Sojo University), Nijihiko Otsuka (Sojo University), Anders Dahl (Technical University of Denmark)
The 35th British Machine Vision Conference

Abstract

We present TopoMortar, a brick wall dataset that is the first dataset specifically designed to evaluate topology-focused image segmentation methods, such as topology loss functions. Motivated by the known sensitivity of methods to dataset challenges, such as small training sets, noisy labels, and out-of-distribution test-set images, TopoMortar is created to enable in two ways investigating methods' effectiveness at improving topology accuracy. First, by eliminating dataset challenges that, as we show, impact the effectiveness of topology loss functions. Second, by allowing to represent different dataset challenges in the same dataset, isolating methods' performance from dataset challenges. TopoMortar includes three types of labels (accurate, pseudo-labels, and noisy labels), two fixed training sets (large and small), and in-distribution and out-of-distribution test-set images. We compared eight loss functions on TopoMortar, and we found that clDice achieved the most topologically accurate segmentations, and that the relative advantageousness of the other loss functions depends on the experimental setting. Additionally, we show that data augmentation and self-distillation can elevate Cross entropy Dice loss to surpass most topology loss functions, and that those simple methods can enhance topology loss functions as well. TopoMortar and our code can be found at https://jmlipman.github.io/TopoMortar

Citation

@inproceedings{Valverde_2025_BMVC,
author    = {Juan Miguel Valverde and Motoya Koga and Nijihiko Otsuka and Anders Dahl},
title     = {TopoMortar: A Dataset to Evaluate Topology Accuracy in Image Segmentation},
booktitle = {36th British Machine Vision Conference 2025, {BMVC} 2025, Sheffield, UK, November 24-27, 2025},
publisher = {BMVA},
year      = {2025},
url       = {https://bmva-archive.org.uk/bmvc/2025/assets/papers/Paper_596/paper.pdf}
}


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