Spline refinement with differentiable rendering

Detecting slender, overlapping structures remains a challenge in computational microscopy. While recent coordinate-based approaches improve detection, they often produce less accurate splines than pixel-based methods. We introduce a training-free differentiable rendering approach to spline refinement, achieving both high reliability and sub-pixel accuracy. Our method improves spline quality, enhances robustness to distribution shifts, and shrinks the gap between synthetic and real-world data. Being fully unsupervised, the method is a drop-in replacement for the popular active contour model for spline refinement. Evaluated on C. elegans nematodes, a popular model organism for drug discovery and biomedical research, we demonstrate that our approach combines the strengths of both coordinate- and pixel-based methods.

@article{zdyb2025_2503.14525,
  title={ Spline refinement with differentiable rendering },
  author={ Frans Zdyb and Albert Alonso and Julius B. Kirkegaard },
  journal={arXiv preprint arXiv:2503.14525},
  year={ 2025 }
}