Development of an automated pigmentation phenotyping and low- cost
multispectral imaging system
Abstract
Canopy imaging is a good phenotyping approach to non-invasively quantify
parameters such as canopy size, stress symptoms, and pigment
concentrations. Unlike destructive measurements, canopy imaging is fast
and easy. However, analysis of the images can be time consuming. To
facilitate large-scale use of imaging, the cost of imaging systems needs
to be reduced and the analysis needs to be automated. We developed
low-cost imaging systems using a Raspberry Pi microcomputer, equipped
with a monochrome camera and filter, at a total hardware cost of
~$500. The latest version of our imaging system takes
images under blue, green, red, and infra-red light, as well as images of
chlorophyll fluorescence. Images taken under red, green, and blue light
can be combined to generate color images. Other colors of light can be
easily added, if desired. The imaging system is easily implemented in
controlled environment agriculture and can be adapted for use in field
settings. We will demonstrate examples of simple imaging techniques and
automated image analysis using the Python programing language. The
multi-spectral imaging system generates normalized difference vegetative
index (NDVI) and anthocyanin content index (ACI) images and histograms,
providing quantitative, spatially-resolved information.