Detecting Melanoma Fairly: Skin Tone Detection and Debiasing for Skin Lesion Classification

Convolutional Neural Networks have demonstrated human-level performance in the classification of melanoma and other skin lesions, but evident performance disparities between differing skin tones should be addressed before widespread deployment. In this work, we utilise a modified variational autoencoder to uncover skin tone bias in datasets commonly used as benchmarks. We propose an efficient yet effective algorithm for automatically labelling the skin tone of lesion images, and use this to annotate the benchmark ISIC dataset. We subsequently use two leading bias unlearning techniques to mitigate skin tone bias. Our experimental results provide evidence that our skin tone detection algorithm outperforms existing solutions and that unlearning skin tone improves generalisation and can reduce the performance disparity between melanoma detection in lighter and darker skin tones.