Surface Modelling of Plants from Stereo Images

Abstract

Plants are characterised by a range of complex and variable attributes, and measuring these attributes accurately and reliably is a major challenge for the industry. In this paper, we investigate creating a surface model of plant from images taken by a stereo pair of cameras. The proposed modelling architecture comprises a fast stereo algorithm to estimate depths in the scene and a model of the scene based on visual appearance and 3D geometry measurements. Our stereo algorithm employs a coarse-fine strategy for disparity estimation. We develop a weighting method and use Kalman filter to refine estimations across scales. A self-organising map is applied to reconstruct a surface from these sample points created by the stereo algorithm. We compare and evaluate our stereo results against other popular stereo algorithms, and also demonstrate that the proposed surface model can be used to extract useful plant features that can be of importance in plant management and assessing quality for marketing.