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 could indicate average of tip angle properly. Further, an outline of three dimensional 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 (Chinese-cabbage and tomato) . Consequently, this method can detect differences between controlled figures and treated ones properly.
