Abstract: The leaves obtained by mobile phones in complex backgrounds are taken as the research objects. According to the results of RGB components feature analysis, the target leaves can be segmented by the Extra-green character (EXG) and the bottom-hat transformation. For removing the background of the green component and the others with large difference, the bottom-hat transformation can be used. While for the other two components with small difference, the Extra-green character can be used. Moreover, in order to reduce the error rate of the segmentation, the Otsu algorithm can be used to modify its details. The result shows that all above of the algorithms can segment the leaves well from the complex backgrounds and all error rates are less than 3.68%.