Adaptive Hue Threshold for Zanthoxylum Bungeanum Fruit Detection

Zanthoxylum bungeanum is very popular in China, and some automatic picking systems or robots are researched to pick the pepper fruit instead of human hands. The detection algorithm is very important for an automatic picking system. HSV color space is commonly used in color image segmentation. After evaluating the fixed threshold for pepper fruit detection, we propose a new method to get an adaptive threshold directly based on the HSV color space, called AHT, which means Adaptive Hue Threshold. The hue threshold is obtained according to the conditions, whether it is the soil, the rock, and the pepper fruit in the image. Our method works very well in typical scenarios.