Research on Recognition Method for Overlapping Tomatoes Based on Depth Map

Overlapping harvesting objects’ recognition is a difficulty of researches in vision system of fruits and vegetables harvesting robots. In order to improve the recognition accuracy rate of overlapping tomatoes, a recognition method of front and back overlapping region is presented, which is based on the automatic threshold image segmentation of depth map. Depth map is obtained through combination stereo matching method based on binocular stereo vision. Denoising processing is applied to depth map before image segmentation of depth map. Segmentation of front and back overlapping region can be realized through iterative OTSU threshold segmentation method because there are obvious difference between front region and back region for depth information. 48 pairs of stereo images have been tested, and the recognition accuracy rate is 96.3%. It shows that this method is effective to recognition of front and back overlapping region. There are also some problems. This method doesn’t adapt to adhesive regions. It should be resolved combining other methods in future researches. This method doesn’t adapt to the images which are grabbed at the distance larger than 800mm either.