Advances in hyperspectral imaging (HSI) and 3D reconstruction methods
have enabled accurate and high-throughput characterization of agricultural
produce quality and plant phenotypes, both of which are essential
for advancing agricultural sustainability and enhancing breeding programs.
HSI effectively captures detailed biochemical features of produce, while 3D
geometric data significantly improves morphological analysis.
However, integrating these two modalities at scale poses significant challenges.
Conventional 3D reconstruction techniques often involve complex hardware
setups that are difficult to integrate into automated phenotyping systems.
Recent advances in neural radiance fields (NeRF) offer computationally
efficient 3D reconstruction but typically require moving-camera setups,
which limit throughput and reproducibility in standard indoor agricultural
phenotyping environments. To address these challenges, we introduce a
stationary-camera-based multi-channel NeRF framework designed explicitly
for high-throughput hyperspectral reconstruction for postharvest inspection
of agricultural produce. Our method captures multi-view hyperspectral data
using a stationary hyperspectral camera by rotating the object in front of
a carefully calibrated dark screen. We then estimate the relative pose of
the rotated object with the help of calibration markers. These poses are
then transformed to the camera frame of reference using simulated pose
transformations, which facilitate NeRF training using standard approaches.
In addition, we convert traditional 3-channel NeRF to use the multiple channels
of the hyperspectral data to calculate the loss. Our approach yield
high-resolution 3D hyperspectral point clouds with high precision-recall
scores. Our results demonstrate that stationary-camera NeRF enables robust
3D hyperspectral reconstruction into automated agricultural workflows.