CorrCLIP
August 16, 2026 · View on GitHub
CorrCLIP
Training-free open-vocabulary semantic segmentation by reconstructing CLIP's patch correlations
This repository hosts two methods. Each subdirectory is self-contained — its own README, configs, dependencies and evaluation scripts — so pick one and work entirely inside it.
| Directory | Method | Status |
|---|---|---|
| CorrCLIPv1/ | CorrCLIP | ICCV 2025 Oral |
| CorrCLIPv2/ | CorrCLIPv2 | Journal extension, under review |
CorrCLIP
CLIP's patch correlations are noisy: patches attend across class boundaries, which blurs the segmentation map. CorrCLIP reconstructs both the scope and the value of those correlations to suppress inter-class attention, strengthens the final patch features with two auxiliary branches, and updates the segmentation map with class-agnostic masks for spatial consistency. No training, no annotation.
→ CorrCLIPv1/README.md · Colab demo
CorrCLIPv2
CorrCLIPv2 keeps that single-image pipeline and adds cross-image semantic support, retrieved from an offline memory bank built purely from unlabeled images — still no annotation, no caption, no training. Two components:
- VISR (VFM-Indexed Semantic Retrieval) builds the bank. A mask generator produces class-agnostic regions for each unlabeled image, and mask average pooling gives one embedding per region from both a vision foundation model and CorrCLIP. The VFM embeddings become the FAISS index keys, the CorrCLIP embeddings the semantic values. At inference each test region retrieves its Top-K neighbors and the returned values are fused with the image's own prediction — retrieval happens in VFM space, decoupled from text and vocabulary.
- DMCE (Decoupled Multi-CLIP Ensemble) stores region features from several CLIP variants under that one index, so auxiliary CLIP representations are retrieved rather than recomputed — ensemble gains at a few milliseconds of overhead.
Pre-generated masks and prebuilt memory banks are published so the results can be reproduced without building a bank: dk258/CorrCLIPv2.
Citation
The journal extension is under review; please cite the conference paper for now:
@article{zhang2024corrclip,
title={Corrclip: Reconstructing patch correlations in clip for open-vocabulary semantic segmentation},
author={Zhang, Dengke and Liu, Fagui and Tang, Quan},
journal={arXiv preprint arXiv:2411.10086},
year={2024}
}