Bootstrapping Semantic Segmentation with Regional Contrast

04/09/2021

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by   Shikun Liu, et al.

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We present ReCo, a contrastive learning framework designed at a regional level to assist learning in semantic segmentation. ReCo performs semi-supervised or supervised pixel-level contrastive learning on a sparse set of hard negative pixels, with minimal additional memory footprint. ReCo is easy to implement, being built on top of off-the-shelf segmentation networks, and consistently improves performance in both semi-supervised and supervised semantic segmentation methods, achieving smoother segmentation boundaries and faster convergence. The strongest effect is in semi-supervised learning with very few labels. With ReCo, we achieve 50 whilst requiring only 20 labelled images, improving by 10 previous state-of-the-art. Code is available at https://github.com/lorenmt/reco.