TY - EJOUR AU - Upschulte, Eric AU - Harmeling, Stefan AU - Amunts, Katrin AU - Dickscheid, Timo TI - Contour Proposal Networks for Biomedical Instance Segmentation JO - Medical image analysis SN - 1361-8415 CY - Amsterdam [u.a.] PB - Elsevier Science M1 - FZJ-2021-02034 SP - 102371 - PY - 2022 AB - We present a conceptually simple framework for object instance segmentation called Contour Proposal Network (CPN), which detects possibly overlapping objects in an image while simultaneously fitting closed object contours using an interpretable, fixed-sized representation based on Fourier Descriptors. The CPN can incorporate state of the art object detection architectures as backbone networks into a single-stage instance segmentation model that can be trained end-to-end. We construct CPN models with different backbone networks, and apply them to instance segmentation of cells in datasets from different modalities. In our experiments, we show CPNs that outperform U-Nets and Mask R-CNNs in instance segmentation accuracy, and present variants with execution times suitable for real-time applications. The trained models generalize well across different domains of cell types. Since the main assumption of the framework are closed object contours, it is applicable to a wide range of detection problems also outside the biomedical domain. An implementation of the model architecture in PyTorch is freely available. LB - PUB:(DE-HGF)25 UR - https://juser.fz-juelich.de/record/892373 ER -