CLIPSelf: Vision Transformer Distills Itself for Open-Vocabulary Dense Prediction

2 Oct 2023  ·  Size Wu, Wenwei Zhang, Lumin Xu, Sheng Jin, Xiangtai Li, Wentao Liu, Chen Change Loy ·

Open-vocabulary dense prediction tasks including object detection and image segmentation have been advanced by the success of Contrastive Language-Image Pre-training (CLIP). CLIP models, particularly those incorporating vision transformers (ViTs), have exhibited remarkable generalization ability in zero-shot image classification. However, when transferring the vision-language alignment of CLIP from global image representation to local region representation for the open-vocabulary dense prediction tasks, CLIP ViTs suffer from the domain shift from full images to local image regions. In this paper, we embark on an in-depth analysis of the region-language alignment in CLIP models, which is essential for downstream open-vocabulary dense prediction tasks. Subsequently, we propose an approach named CLIPSelf, which adapts the image-level recognition ability of CLIP ViT to local image regions without needing any region-text pairs. CLIPSelf empowers ViTs to distill itself by aligning a region representation extracted from its dense feature map with the image-level representation of the corresponding image crop. With the enhanced CLIP ViTs, we achieve new state-of-the-art performance on open-vocabulary object detection, semantic segmentation, and panoptic segmentation across various benchmarks. Models and code are released at https://github.com/wusize/CLIPSelf.

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Task Dataset Model Metric Name Metric Value Global Rank Benchmark
Open Vocabulary Panoptic Segmentation ADE20K CLIPSelf PQ 23.7 # 3
Open Vocabulary Semantic Segmentation ADE20K-150 CLIPSelf mIoU 34.5 # 4
Open Vocabulary Semantic Segmentation ADE20K-847 CLIPSelf mIoU 12.4 # 8
Open Vocabulary Object Detection LVIS v1.0 CLIPSelf AP novel-LVIS base training 34.9 # 3
Open Vocabulary Object Detection MSCOCO CLIPSelf AP 0.5 44.3 # 5
Open Vocabulary Semantic Segmentation PASCAL Context-59 CLIPSelf mIoU 62.3 # 3

Methods