Open-Vocabulary Semantic Segmentation Using Test-Time Distillation

Semantic segmentation is a key computer vision task that has been actively researched for decades. In recent years, supervised methods have reached unprecedented accuracy; however, obtaining pixel-level annotation is very time-consuming and expensive. In this paper, we propose a novel open-vocabulary approach to creating semantic segmentation masks, without the need for training segmentation networks or seeing any segmentation masks. At test time, our method takes as input the image-level labels of the categories present in the image. We utilize a vision-language embedding model to create a rough segmentation map for each class via model interpretability methods and refine the maps using a test-time augmentation technique. The output of this stage provides pixel-level pseudo-labels, which are utilized by single-image segmentation techniques to obtain high-quality output segmentations. Our method is shown quantitatively and qualitatively to outperform methods that use a similar amount of supervision, and to be competitive with weakly-supervised semantic-segmentation techniques.