A Study on Virtual Plant System Based on Machine Vision

• Main Authors: Wen-Chi Liao, 廖文棋
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/58680938812347825405

碩士 === 國立臺灣大學 === 生物產業機電工程學研究所 === 89 === 　A virtual plant system based on parametric L-system and bracketed L-system was developed in this research. The virtual plant system used two layers of rules to describe the branching structures and the growth of plants. 3D graphics library was used to present 3D images of virtual plants modeled with curly cylindrical stems and leaves composed of parametric surface and texture. In order to efficiently construct a virtual plant, a digitizing system employing stereo machine vision to acquire the geometric information such as position, angle, length of internode and leaves was also developed. The digitized coordinates were used to construct the structure of virtual plant and translate into the state string of our L-systems for further calculation of plant characteristics. The performance of the machine vision system was tested with the measurement of the characteristics of pepper, collard, cabbage and Chinese cabbage seedlings. The experimental results showed that the RMSE of internode were less than 1 mm, and the RMSE of total leaf area were less than 2 cm2. The machine vision system can also be used for nondestructive growth measurement of plants. Two sets of experiments were performed. In the first experiment, the characteristics of cabbage seedlings were measured continuously as they grew. The growth curves of total leaf area, single leaf area, the length of stem, etc. were determined and analyzed. In the second experiment, we measured the growth curves of pepper seedlings cultured in pots with different sized to compare the effect of medium quantity on the growth pepper seedlings. Besides the construction of virtual plants for vegetable seedlings in the previous experiments, virtual plants of 7 other plants with different shapes and structures were also constructed to test and discuss the versatility and limitation of the virtual plant system developed in this research.