Multispectral Registration, Undistortion and Tree Detection for Precision Agriculture

Abstract

Multi-lens multispectral cameras allow us to record multispectral information for a whole area of terrain, even though we may only need the vegetation data. Based on the intensity of each multispectral image we can retrieve the contours of the trees that appear on the recorded terrain. However, multispectral cameras use a physically different lens for each range of wavelengths and misregistration effects could appear due to the different viewing positions. As these types of lenses are dedicated to capture larger areas of terrain, their focal distance is lower and because of this we get what is called a fisheye distortion. Therefore if we want to retrieve the shape of each tree and its multispectral data we need to process the channels so them all are representated as undistorted images under a same reference system.