Color Analysis of Leaf Images of Deficiencies and Excess Nitrogen Content in Soybean Leaves

Deficiencies and excess of soybean's plant nitrogen is the key of soybean nutritional diagnosis. Applying image processing technique, this paper studied the leaf images of the six stages of soybean growth, which nitrogen fertilizer applied were 0%, 50%, 100% and 150%. Using image preprocessing, the noise of source image was removed and the areas of interest were enhanced, leaves and background were separated using minimum error threshold method. The color characters of soybean leaves were analyzed using the RGB and the HSI model. The standard of distinction between normal and excessive loss of soybean leaves was found, which proved technical basis of the diagnosis of deficiencies and excess of soybean's plant nitrogen.