Measuring And Extracting Rice Canopy Structural Parameters Based On Hemispherical Photograph

Canopy is the main place for crops to interact with external environment. It is very important to obtain canopy structure parameters for crops grow monitoring, biomass estimation and some crops growth simulation model. Traditional canopy structure parameters determination methods are time-consuming and arduous, and usually are destructive. In order to measure rice canopy structure parameters conveniently, quickly and non-destructive, we adopted a self-made digital hemispheric photography system to collect rice canopy data in different growth periods. We also developed software to extract gap fraction of different view angles from fish-eye images of rice canopy, and turn gap fraction to several of canopy structural parameters such as leaf area index (LAI) and mean leaf angle (MLA). Canopy structural parameters were compared to those acquired from manual method and AccuPAR LP-80. The correlation between them is good.(1) Research on rice canopy structure parameters inversion method By comparative study on plant canopy structure expression and measuring methods, we study which canopy structure parameters and measuring methods are suitable for rice plants. We finally adopted the method that based on Beer-Lambert law to invert canopy structure parameters using gap fraction data. Hemispherical rice canopy images were collected using a hemispherical photography system, and were used to extract view-angle-related gap fraction form hemispherical rice canopy images.(2) Develop a rice canopy structure parameters inversion software Appling digital image processing technology, we development software to automatic segment rice canopy from background, and to extract the multiple view angles of rice canopy gap fraction in hemispheric images. By canopy gap fraction, the software can calculate various types of canopy structural parameters including LAI and MLA.(3) Verify the correctness and reliability of the model and method In order to validate the correctness and reliability of the system, we carried out many times of field testing on rice canopy structural parameters obtain. In field testing, we compare results from our work to those from manual measurement method and AccuPAR LP-80 plants canopy analyzer. Results from different methods shown good correlation that square of correlation coefficients above 0.6...