3D Reconstruction-Based Seed Counting of Sorghum Panicles for Agricultural Inspection
Harry Freeman, Eric Schneider, Chung Hee Kim, Moonyoung Lee, George Kantor
TL;DR
This work tackles non-destructive sorghum seed counting by constructing high-quality 3D panicle models that leverage seeds as semantic landmarks in 2D and 3D. It introduces a seed-centered reconstruction pipeline, a cloud-only reconstruction quality metric, and a 3D counting method that uses DBSCAN clustering, Gaussian density smoothing, and local maxima to identify seed centers. Experimental results on a dataset of 100 panicles show a strong linear relationship between 3D counts and ground-truth seeds (R² = 0.875) with a RMSE of 295 seeds, and a seed-weight correlation of R² = 0.819 (RMSE ≈ 8.5 g). The study demonstrates that 3D counting outperforms 2D extrapolation, justifying the added hardware complexity for improved accuracy in yield-related phenotyping and robotic agriculture applications.
Abstract
In this paper, we present a method for creating high-quality 3D models of sorghum panicles for phenotyping in breeding experiments. This is achieved with a novel reconstruction approach that uses seeds as semantic landmarks in both 2D and 3D. To evaluate the performance, we develop a new metric for assessing the quality of reconstructed point clouds without having a ground-truth point cloud. Finally, a counting method is presented where the density of seed centers in the 3D model allows 2D counts from multiple views to be effectively combined into a whole-panicle count. We demonstrate that using this method to estimate seed count and weight for sorghum outperforms count extrapolation from 2D images, an approach used in most state of the art methods for seeds and grains of comparable size.
