AlignSAM: Aligning Segment Anything Model to Open Context via Reinforcement Learning
Duojun Huang, Xinyu Xiong, Jie Ma, Jichang Li, Zequn Jie, Lin Ma, Guanbin Li
TL;DR
This work introduces AlignSAM, a framework that adapts the Segment Anything Model to open contexts without altering SAM’s parameters. It employs a reinforcement-learning prompting agent to select informative patch-level prompts, progressively refining segmentation, while a semantic recalibration module provides reliable labels and supports both explicit and implicit semantics through explicit and implicit branches. The approach combines patch-level action spaces, PPO-based training, and cross-modal cues (via CLIP-inspired attention) to achieve robust, task-aware prompting. Empirical results across blur, shadow, glass, saliency, and Pascal-VOC tasks show AlignSAM outperforming state-of-the-art efficient-tuning and prompting methods, with ablations confirming the critical roles of RL, SRM, and multi-step prompting in driving gains.
Abstract
Powered by massive curated training data, Segment Anything Model (SAM) has demonstrated its impressive generalization capabilities in open-world scenarios with the guidance of prompts. However, the vanilla SAM is class agnostic and heavily relies on user-provided prompts to segment objects of interest. Adapting this method to diverse tasks is crucial for accurate target identification and to avoid suboptimal segmentation results. In this paper, we propose a novel framework, termed AlignSAM, designed for automatic prompting for aligning SAM to an open context through reinforcement learning. Anchored by an agent, AlignSAM enables the generality of the SAM model across diverse downstream tasks while keeping its parameters frozen. Specifically, AlignSAM initiates a prompting agent to iteratively refine segmentation predictions by interacting with the foundational model. It integrates a reinforcement learning policy network to provide informative prompts to the foundational models. Additionally, a semantic recalibration module is introduced to provide fine-grained labels of prompts, enhancing the model's proficiency in handling tasks encompassing explicit and implicit semantics. Experiments conducted on various challenging segmentation tasks among existing foundation models demonstrate the superiority of the proposed AlignSAM over state-of-the-art approaches. Project page: \url{https://github.com/Duojun-Huang/AlignSAM-CVPR2024}.
