Papers › Zero-Shot Out-of-Distribution Detection Based on the Pre-trained Model CLIP

Zero-Shot Out-of-Distribution Detection Based on the Pre-trained Model CLIP

6 Sep 2021arXiv:2109.02748archive 2025-07-28

Sepideh Esmaeilpour, Bing Liu, Eric Robertson, Lei Shu

In an out-of-distribution (OOD) detection problem, samples of known classes(also called in-distribution classes) are used to train a special classifier. In testing, the classifier can (1) classify the test samples of known classes to their respective classes and also (2) detect samples that do not belong to any of the known classes (i.e., they belong to some unknown or OOD classes). This paper studies the problem of zero-shot out-of-distribution(OOD) detection, which still performs the same two tasks in testing but has no training except using the given known class names. This paper proposes a novel yet simple method (called ZOC) to solve the problem. ZOC builds on top of the recent advances in zero-shot classification through multi-modal representation learning. It first extends the pre-trained language-vision model CLIP by training a text-based image description generator on top of CLIP. In testing, it uses the extended model to generate candidate unknown class names for each test sample and computes a confidence score based on both the known class names and candidate unknown class names for zero-shot OOD detection. Experimental results on 5 benchmark datasets for OOD detection demonstrate that ZOC outperforms the baselines by a large margin.

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sesmae/zoc officialmentioned in papermentioned on GitHubpytorchMIT report
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tokenize_for_clip sesmae/zoc/tinyimagenet_eval.py official repository ran · honoured contract MIT (permissive) · 586e23a21dc8d140 · report
eval_decoder sesmae/zoc/train_decoder.py official repository unverified MIT (permissive) · 1e88096b561d13b7 · report
get_bert_training_features sesmae/zoc/dataloaders/coco_full_loader.py official repository unverified MIT (permissive) · ad6951f135361d60 · report
get_bos_sentence_eos sesmae/zoc/dataloaders/coco_full_loader.py official repository unverified MIT (permissive) · f39b19abd2c9cd41 · report
get_clip_image_features sesmae/zoc/dataloaders/coco_full_loader.py official repository unverified MIT (permissive) · 37742137dd850137 · report
greedysearch_generation_topk sesmae/zoc/tinyimagenet_eval.py official repository unverified MIT (permissive) · 1eac11a38598f275 · report
greedysearch_generation_topk sesmae/zoc/cifar100_eval.py official repository unverified MIT (permissive) · 27650a2ee702a0cb · report
greedysearch_generation_topk sesmae/zoc/cifar10_eval.py official repository unverified MIT (permissive) · e96829e6d222df08 · report
image_decoder sesmae/zoc/tinyimagenet_eval.py official repository unverified MIT (permissive) · 1baaac6c70ab5a06 · report
image_decoder sesmae/zoc/cifar100_eval.py official repository unverified MIT (permissive) · ea251c0ac6fabe91 · report
train_decoder sesmae/zoc/train_decoder.py official repository unverified MIT (permissive) · 9775c2c477077546 · report

Tasks

Out of Distribution (OOD) DetectionOut-of-Distribution DetectionRepresentation LearningZero-Shot Learning

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Methods

CLIP

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