In order to improve our competitiveness in international sales of fruit on the market, improve the fruit quality and storage period, fruit before listing has become a commodity, it must be cleaned, processing treatment on post harvest products, then according to the size and quality grading standards for sorting, deep processing and packaging etc.. On the one hand, fruit sorting can not only to promote market circulation, improve food hygiene and safety as well as the origin of credibility, and through sorting, finishing to improve product quality, to achieve higher prices for better quality. This is the only way to producers and operators of equal competition, increase the efficiency of the. On the other hand, if the sales, storage or processing of fruit wax spraying and sorting, can avoid the separation process of damage, increased fruit storage time, improves the fruit processing quality and export grade, reduce the loss, but also can improve the storage quality, from bacterial infection. To meet the consumption demand, which has important economic and practical significance to increase the export competitiveness of China's fruit.

The machine vision technology, different specifications of the size and appearance of qualified fruit sorting. There are two methods of classification used widely, is a mere human visual judgment, according to fruit color, size will be divided into several grade products. Using this method to grade products, the level is easily affected by psychological factors, often large deviation. Two is a fruit plate classification, selection of a series of different diameter bore fruit plate, fruit diameter were classified according to different area and coloring. Using this method to grade products, the same grade fruit size consistent, smaller deviation. Artificial classification can minimize the mechanical damage of fruit, applicable to all kinds of fruits. But this classification method needs a large amount of labor force, labor strength is great, and the subjective assessment by the individual vision, color discrimination, mood, fatigue, light and other factors, low efficiency, poor accuracy, can not guarantee strictly according to the classification standard of fruit grading.