Zero shot 3D plant segmentation works without manual training data

Zero-Shot 3D Plant Organ Segmentation with SAM3 and Semantic NeRFs

Computer Vision and Pattern Recognition

Summary

Segmenting parts of plants in 3D images usually needs lots of labeled examples or special models for each plant type. The authors created a method that doesn't require any manual labeling or special tuning for different plants. Their system takes multiple photos and just a list of plant part names, then creates accurate 3D segmentations automatically. They tested it on various plants and found the results nearly as good as supervised methods that use labeled data. This shows plant 3D segmentation can be done without costly manual work.

3D plant segmentationzero shot learningSAM3semantic neural radiance fieldsNeRFmulti-view imagingpoint cloudautomated phenotypingmean intersection over unionannotation free

Authors

Andreas Gilson, Laura Hennig, Peter Pietrzyk

Abstract

Accurate 3D plant organ segmentation is fundamental to automated phenotyping. Existing approaches rely on annotated training data or species-specific model configurations. We present an annotation-free pipeline for 3D plant organ segmentation, combining text-prompted SAM3 segmentation with semantic neural radiance fields (NeRFs). Given only multi-view RGB images and a list of class names, our zero-shot pipeline produces semantically labeled 3D point clouds without manual annotation, per-species fine-tuning, or domain-specific preprocessing. Multi-view NeRF fusion acts as effective implicit consensus mechanism that lifts imperfect per-frame masks into accurate 3D labels. On a controlled Begonia maculata testbed the SAM3 pipeline achieves 92.6% mIoU, reaching 95.9% of the oracle upper bound established with perfect ground-truth masks. The pipeline was further evaluated on a new dataset spanning ten diverse plant point clouds reaching an average 0.856 mIoU, with leaf and pot IoU above 0.91 and 0.90 for every species, respectively. These results demonstrate that annotation-free 3D plant organ segmentation is now feasible and approaching the range of supervised methods.