Analysis of Autumnal Leaf Colorization of Sapium sebiferum by Using Physiological and Digital Imaging Methods Obtaining Information of Cotton Population Chlorophyll by Using Machine Vision Technology A quantitative analysis method for measuring grassland coverage based on the RGB model Preliminary Study on Relationship between Pigments and Flesh Color of Sweetpotato Based on the Characteristic Values of image RGB Acquired Chlorophyll Concentration of Cotton Leaves with Technology of Machine Vision