1. Introduction
Currently, fruits sorting mostly depend on manual method which results in low efficiency, and annually lots of labor and finance is consumed. During the I970s machine vision has been widely used in the field of varietal recognition because of the specialization of image processing, lower cost and higher speed of computer and its many features. Machine vision system is mainly used for obtaining information of the working environment and performs detection and orientation of operation target. People have presented various methods for image recognition. Image matching is one of the most widely used methods.