🤖 AI Summary
To address the high computational and memory overhead of SAM2 in video object segmentation caused by dense visual tokens, this paper proposes a text-guided post-encoding visual token pruning framework. Without modifying the original model architecture, the method dynamically evaluates and retains critical tokens by jointly leveraging local visual context, text–visual semantic alignment, and uncertainty modeling. It introduces, for the first time, user- or auto-generated textual prompts into the post-encoding importance scoring process, enabling semantic-aware early sparsification prior to temporal propagation. Key design elements include a lightweight routing mechanism, multi-source importance fusion, and decoupling of the image encoder from the memory module. Experiments across multiple benchmarks demonstrate a 42.50% speedup in inference latency and a 37.41% reduction in GPU memory consumption, while maintaining near-equivalent J&F scores—significantly enhancing the deployability of Transformer-based video segmentation models in real-time and edge-computing scenarios.
📝 Abstract
Segment Anything Model 2 (SAM2), a vision foundation model has significantly advanced in prompt-driven video object segmentation, yet their practical deployment remains limited by the high computational and memory cost of processing dense visual tokens across time. The SAM2 pipelines typically propagate all visual tokens produced by the image encoder through downstream temporal reasoning modules, regardless of their relevance to the target object, resulting in reduced scalability due to quadratic memory attention overhead. In this work, we introduce a text-guided token pruning framework that improves inference efficiency by selectively reducing token density prior to temporal propagation, without modifying the underlying segmentation architecture. Operating after visual encoding and before memory based propagation, our method ranks tokens using a lightweight routing mechanism that integrates local visual context, semantic relevance derived from object-centric textual descriptions (either user-provided or automatically generated), and uncertainty cues that help preserve ambiguous or boundary critical regions. By retaining only the most informative tokens for downstream processing, the proposed approach reduces redundant computation while maintaining segmentation fidelity. Extensive experiments across multiple challenging video segmentation benchmarks demonstrate that post-encoder token pruning provides a practical and effective pathway to efficient, prompt-aware video segmentation, achieving up to 42.50 percent faster inference and 37.41 percent lower GPU memory usage compared to the unpruned baseline SAM2, while preserving competitive J and F performance. These results highlight the potential of early token selection to improve the scalability of transformer-based video segmentation systems for real-time and resource-constrained applications.