DiffKillR: Killing and Recreating Diffeomorphisms for Cell Annotation in Dense Microscopy Images
Chen Liu, Danqi Liao, Alejandro Parada-Mayorga, Alejandro Ribeiro, Marcello DiStasio, Smita Krishnaswamy
TL;DR
DiffKillR tackles the challenge of dense cell annotation in microscopy by reframing labeling as archetype matching followed by diffeomorphic image registration. It introduces two networks: DiffeoInvariantNet, which learns a diffeomorphism-invariant cell representation for robust archetype matching, and DiffeoMappingNet, which computes forward and inverse warping fields $\,\mathcal{W}$ and $\mathcal{W}^{-1}$ to recreate and transfer pixel-level annotations between matched cells. Theoretical guarantees from algebraic-signal processing establish that a finite set of deformations suffices to represent bandlimited diffeomorphisms and provide an error bound for cell matching, while empirical results demonstrate strong performance on cell counting, orientation prediction, and few-shot segmentation with reduced labeling. The approach enables versatile, label-efficient annotation across diverse microscopy tasks and offers practical impact for histology analysis and clinical diagnostics.
Abstract
The proliferation of digital microscopy images, driven by advances in automated whole slide scanning, presents significant opportunities for biomedical research and clinical diagnostics. However, accurately annotating densely packed information in these images remains a major challenge. To address this, we introduce DiffKillR, a novel framework that reframes cell annotation as the combination of archetype matching and image registration tasks. DiffKillR employs two complementary neural networks: one that learns a diffeomorphism-invariant feature space for robust cell matching and another that computes the precise warping field between cells for annotation mapping. Using a small set of annotated archetypes, DiffKillR efficiently propagates annotations across large microscopy images, reducing the need for extensive manual labeling. More importantly, it is suitable for any type of pixel-level annotation. We will discuss the theoretical properties of DiffKillR and validate it on three microscopy tasks, demonstrating its advantages over existing supervised, semi-supervised, and unsupervised methods. The code is available at https://github.com/KrishnaswamyLab/DiffKillR.
