A High Throughput Integrated Hyperspectral Imaging and 3D Measurement System.

Huijie Zhao,Hongzhi Jiang,Shaoguang Shi,Lunbao Xu,Da Chen

doi:10.3390/s18041068

Abstract

Hyperspectral and three-dimensional measurements can obtain the intrinsic physicochemical properties and external geometrical characteristics of objects, respectively. The combination of these two kinds of data can provide new insights into objects, which has gained attention in the fields of agricultural management, plant phenotyping, cultural heritage conservation, and food production. Currently, a variety of sensors are integrated into a system to collect spectral and morphological information in agriculture. However, previous experiments were usually performed with several commercial devices on a single platform. Inadequate registration and synchronization among instruments often resulted in mismatch between spectral and 3D information of the same target. In addition, using slit-based spectrometers and point-based 3D sensors extends the working hours in farms due to the narrow field of view (FOV). Therefore, we propose a high throughput prototype that combines stereo vision and grating dispersion to simultaneously acquire hyperspectral and 3D information. Furthermore, fiber-reformatting imaging spectrometry (FRIS) is adopted to acquire the hyperspectral images. Test experiments are conducted for the verification of the system accuracy, and vegetation measurements are carried out to demonstrate its feasibility. The proposed system is an improvement in multiple data acquisition and has the potential to improve plant phenotyping.

Highlights

The constantly increasing global population presents a tremendous challenge for agricultural production [1]
We mainly aim to develop an integrated prototype that combines stereo vision based on triangulation for depth information acquisition and snapshot imaging based on grating dispersion for spectral data acquisition
We propose a high throughput prototype capable of simultaneously acquiring hyperspectral images and 3D structures

Summary

Introduction

The constantly increasing global population presents a tremendous challenge for agricultural production [1]. Improving crop varieties and developing precision agriculture have become key steps to increasing yield [2,3], inseparably linked to the ability to assess the phenotype of plants [4]. The measurements of thousands of plants are laborious and time consuming, and obtaining sufficient phenotypic data on a single plot remains problematic [1]. High quality plant phenotypic data and uncontrollable environmental conditions are two major challenges for field-based strategies [5]. Light coming out of the slit is dispersed by grating and focused on the detector. In contrast to plate grating, concave grating combines the functions of light dispersion and focusing, thereby ensuring that the spectrometer is compact and portable [34].

Results

Discussion

Conclusion