Prior-guided Diffusion Model for Cell Segmentation in Quantitative Phase Imaging
Zhuchen Shao, Mark A. Anastasio, Hua Li
TL;DR
This work tackles the inefficiency of diffusion-model based cell segmentation in quantitative phase imaging by introducing prior-guided starting noise. It presents a two-LDM framework (LDM-P for content priors and LDM-S for segmentation) with DDIM inversion to convert input images into content-informed noise, enabling accurate single-sample segmentation. Extensive experiments on HeLa and CHO QPI datasets show that PG-DiffSeg achieves state-of-the-art or competitive results with a single sampling, outperforming traditional deterministic methods and many multi-sample diffusion baselines. Ablation studies corroborate the value of content priors and DDIM inversion for preserving structure while maintaining Gaussian-like noise, highlighting practical gains in speed and accuracy for label-free cell segmentation.
Abstract
Purpose: Quantitative phase imaging (QPI) is a label-free technique that provides high-contrast images of tissues and cells without the use of chemicals or dyes. Accurate semantic segmentation of cells in QPI is essential for various biomedical applications. While DM-based segmentation has demonstrated promising results, the requirement for multiple sampling steps reduces efficiency. This study aims to enhance DM-based segmentation by introducing prior-guided content information into the starting noise, thereby minimizing inefficiencies associated with multiple sampling. Approach: A prior-guided mechanism is introduced into DM-based segmentation, replacing randomly sampled starting noise with noise informed by content information. This mechanism utilizes another trained DM and DDIM inversion to incorporate content information from the to-be-segmented images into the starting noise. An evaluation method is also proposed to assess the quality of the starting noise, considering both content and distribution information. Results: Extensive experiments on various QPI datasets for cell segmentation showed that the proposed method achieved superior performance in DM-based segmentation with only a single sampling. Ablation studies and visual analysis further highlighted the significance of content priors in DM-based segmentation. Conclusion: The proposed method effectively leverages prior content information to improve DM-based segmentation, providing accurate results while reducing the need for multiple samplings. The findings emphasize the importance of integrating content priors into DM-based segmentation methods for optimal performance.
