Erasing CLIP Memories: Non-Destructive, Data-Free Zero-Shot class Unlearning in CLIP Models

Fuente: arXiv
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Autori principali: Mishra, Ashish, Kumar, Tarun, Nayak, Gyanaranjan, Shah, Arpit, Bhattacharya, Suparna, Foltin, Martin
Natura: Preprint
Pubblicazione: 2025
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author Mishra, Ashish
Kumar, Tarun
Nayak, Gyanaranjan
Shah, Arpit
Bhattacharya, Suparna
Foltin, Martin
author_facet Mishra, Ashish
Kumar, Tarun
Nayak, Gyanaranjan
Shah, Arpit
Bhattacharya, Suparna
Foltin, Martin
contents We introduce a novel, closed-form approach for selective unlearning in multimodal models, specifically targeting pretrained models such as CLIP. Our method leverages nullspace projection to erase the target class information embedded in the final projection layer, without requiring any retraining or the use of images from the forget set. By computing an orthonormal basis for the subspace spanned by target text embeddings and projecting these directions, we dramatically reduce the alignment between image features and undesired classes. Unlike traditional unlearning techniques that rely on iterative fine-tuning and extensive data curation, our approach is both computationally efficient and surgically precise. This leads to a pronounced drop in zero-shot performance for the target classes while preserving the overall multimodal knowledge of the model. Our experiments demonstrate that even a partial projection can balance between complete unlearning and retaining useful information, addressing key challenges in model decontamination and privacy preservation.
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id arxiv_https___arxiv_org_abs_2512_14137
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Erasing CLIP Memories: Non-Destructive, Data-Free Zero-Shot class Unlearning in CLIP Models
Mishra, Ashish
Kumar, Tarun
Nayak, Gyanaranjan
Shah, Arpit
Bhattacharya, Suparna
Foltin, Martin
Computer Vision and Pattern Recognition
We introduce a novel, closed-form approach for selective unlearning in multimodal models, specifically targeting pretrained models such as CLIP. Our method leverages nullspace projection to erase the target class information embedded in the final projection layer, without requiring any retraining or the use of images from the forget set. By computing an orthonormal basis for the subspace spanned by target text embeddings and projecting these directions, we dramatically reduce the alignment between image features and undesired classes. Unlike traditional unlearning techniques that rely on iterative fine-tuning and extensive data curation, our approach is both computationally efficient and surgically precise. This leads to a pronounced drop in zero-shot performance for the target classes while preserving the overall multimodal knowledge of the model. Our experiments demonstrate that even a partial projection can balance between complete unlearning and retaining useful information, addressing key challenges in model decontamination and privacy preservation.
title Erasing CLIP Memories: Non-Destructive, Data-Free Zero-Shot class Unlearning in CLIP Models
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2512.14137