🤖 AI Summary
To address the limitations in microscopy cell counting—namely, model complexity and the entanglement of localization and counting tasks, which jointly hinder accuracy and efficiency—this paper proposes a decoupled dual-network framework. The framework separates counting and localization: a lightweight Counter network extracts global features to generate a coarse density map and outputs an accurate total cell count; a Locator network, conditioned on both the original image and the coarse map, reconstructs a high-resolution density map for precise single-cell localization. To alleviate optimization difficulties inherent in direct high-resolution density map regression, we introduce a novel cross-regional global message-passing module. The architecture employs a compact two-branch CNN with intermediate-layer feature fusion and conditional density map reconstruction. Evaluated on four standard benchmarks, our method achieves state-of-the-art performance, significantly reducing average counting error. The source code is publicly available.
📝 Abstract
Cell counting in microscopy images is vital in medicine and biology but extremely tedious and time-consuming to perform manually. While automated methods have advanced in recent years, state-of-the-art approaches tend to increasingly complex model designs. In this paper, we propose a conceptually simple yet effective decoupled learning scheme for automated cell counting, consisting of separate counter and localizer networks. In contrast to jointly learning counting and density map estimation, we show that decoupling these objectives surprisingly improves results. The counter operates on intermediate feature maps rather than pixel space to leverage global context and produce count estimates, while also generating coarse density maps. The localizer then reconstructs high-resolution density maps that precisely localize individual cells, conditional on the original images and coarse density maps from the counter. Besides, to boost counting accuracy, we further introduce a global message passing module to integrate cross-region patterns. Extensive experiments on four datasets demonstrate that our approach, despite its simplicity, challenges common practice and achieves state-of-the-art performance by significant margins. Our key insight is that decoupled learning alleviates the need to learn counting on high-resolution density maps directly, allowing the model to focus on global features critical for accurate estimates. Code is available at https://github.com/MedAITech/DCL.