An automatic sorting system for fresh white button mushrooms based on image processing

•An automatic sorting system for fresh white button mushroom is proposed.•An image processing algorithm is introduced to obtain the maximum diameter of pileus.•A precise control strategy based on universal serial bus is introduced.•The system consists of a conveying mechanism, an image acquisition system, a control module and an actuator.•The system achieves online automatic sorting and grading of fresh white button mushrooms with minimal destruction.