Research of image measurement of shape information for identification of growth status of young plants

1997 Fiscal Year Final Research Report Summary

• Project/Area Number: 08660315
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 生物環境
• Research Institution: IWATE UNIVERSITY
• Principal Investigator: SHONO Hiroshi Iwate University, Department of Agronomy and Forestry Research Assistant Professor, 農学部・農林生産学科, 助手 (90235721)
• Project Period (FY): 1996 – 1997
• Keywords: image analysis / image processing / image measurement / texture analysis / three dimensional leaf tip angle distribution / 分光分析

Research Abstract

Features of figure of plant have been expected as useful indices of status of growth. For example, leaf tip angle is known as a significant index of inner water potential status. However, it is very difficult to measure leaf tip angle of all foliages manually. Efficient method of measuring leaf tip angle is necessary. In this paper, a new method of image measurement of leaf tip angle for small foliage or seedling was proposed and its availability was studied. Wedge-shaped feature, which is one of textural features, contains information about tip angle of line in image. Using this characteristic, the method of measuring both average and three dimensional distribution of leaf tip angle was developed. First, fundamental availability of this method was confirmed with simulated images which contain a lot of small three dimensional disks randomly distributed in a cubic area. As a result, wedge-shaped features can indicate average of tip angle properly. Further, an outline of three dimensiona l distribution of tip angle was reconstructed properly from two dimensional distributions of tip angle derived from images taken from several directions. Second, practical availability of this method was studied with images of real plants. Consequently, this method can detect differences between controlled figures and treated ones properly.
Three dimensional distribution of leaf tip angle and three dimensional outline of shape of tomato plants were measured by the method of image measurement based on textural features, and its availability was verified. An algorithm for simplifying the complicated information for efficient transaction was proposed. From discussions on the results, the following conclusions were derived. (1) three dimensional distribution of leaf tip angle and three dimensional outline of shape of tomato plants can be measured separately fairly well especially in upper and younger regions. (2) because crowded leaves in lower and older regions have different tendencies in leaf tip angle between inner layer and outer one, three dimensional measurement is very effective for measuring the proper condition of leaf tip angle. Principal component analysis was applied to obtain understandable indices. The analysis is helpful in understanding the meaning of the shape information.