Yoshinori Gejima

Judgment on level of maturity for tomato quality using L*a*b* color image processing

This paper was described the judgment of Maturity for Tomato quality using color image processing. The image analysis were used for the RGB and L*a*b* color system. In the analyzes, the pixels count of G(36) showed the highest correlation coefficient from tomato maturity. But, the average value of a* of the tomato upper surface was more accurate maturity index than the radical regression curve of G(36).

Basic Study on Strawberry Harvesting Robot (Part II)

Abstract These papers describe a strawberry harvesting robot where by robot vision and a 4 DOF’s Cartesian coordinate manipulator were used. This first part presents the development of a robot vision system and the algorithm for locating and feature extracting of strawberry fruits. The robot vision system employs the use of two color CCD cameras. The first camera is used to capture the whole area image under focus within the harvesting range, and the second camera captures only the image of the strawberry fruit to be plucked. The algorithm converts the captured images from RGB to L*a*b and extracts recognized position, orientation and shape of strawberry from a gray image of the L*a*b color model. Experimental results show that the robot vision system can extract position, orientation and shape of various strawberries in ordinary lighting condition. The Part II presents the design and development of the robot frame, the plucking hand, 4 DOF’s Cartesian coordinate manipulator and the Control System.

Study on Quality Estimation for Strawberry using Color and NIR Image Processing

Abstract This study was carried out to detect bruises on the surface of strawberry using color and NIR image processing. The bruises in this study were caused in controlled manner on the freshly harvested fruits. Firstly, the bruises were detected by analyzing L*a*b* color model. The a* level has indicated their characteristics. Secondly, the particular wavelengths critical for bruise detection were determined and spectral images were acquired with suitable filters of 860 and 960nm. Two methods of image subtractions, one between the same samples and next between the test and standard image, has confirmed the possibilities of bruise detection by using NIR image processing for online sorting.