AnyPattern: Towards In-context Image Copy Detection

TL;DR

This paper introduces AnyPattern, a large-scale dataset for in-context image copy detection (ICD), and proposes ImageStacker, a method that improves generalization to unseen tampering patterns without additional training.

Contribution

It presents the first large-scale pattern dataset for ICD, demonstrates the limitations of existing methods, and proposes ImageStacker to enhance in-context pattern recognition without fine-tuning.

Findings

Training on AnyPattern improves pattern generalization by 26.66% μAP.

ImageStacker increases in-context ICD performance by 16.75% μAP.

AnyPattern enables effective in-context learning for unseen tampering patterns.

Abstract

This paper explores in-context learning for image copy detection (ICD), i.e., prompting an ICD model to identify replicated images with new tampering patterns without the need for additional training. The prompts (or the contexts) are from a small set of image-replica pairs that reflect the new patterns and are used at inference time. Such in-context ICD has good realistic value, because it requires no fine-tuning and thus facilitates fast reaction against the emergence of unseen patterns. To accommodate the "seen $\rightarrow$ unseen" generalization scenario, we construct the first large-scale pattern dataset named AnyPattern, which has the largest number of tamper patterns ($90$ for training and $10$ for testing) among all the existing ones. We benchmark AnyPattern with popular ICD methods and reveal that existing methods barely generalize to novel patterns. We further propose a simple in-context ICD method named ImageStacker. ImageStacker learns to select the most representative image-replica pairs and employs them as the pattern prompts in a stacking manner (rather than the popular concatenation manner). Experimental results show (1) training with our large-scale dataset substantially benefits pattern generalization ($+26.66 \%$ $\mu AP$), (2) the proposed ImageStacker facilitates effective in-context ICD (another round of $+16.75 \%$ $\mu AP$), and (3) AnyPattern enables in-context ICD, i.e., without such a large-scale dataset, in-context learning does not emerge even with our ImageStacker. Beyond the ICD task, we also demonstrate how AnyPattern can benefit artists, i.e., the pattern retrieval method trained on AnyPattern can be generalized to identify style mimicry by text-to-image models. The project is publicly available at https://anypattern.github.io.