Possibilities of Checking Cracks of Brown Rice Using Illumination by Oblique Ray and Image Data Processing System

Abstract

Image Data Processing System was employed to checking cracks of nonglutinous brown rice of short grain, staple food in Japan.
Results obtained were as follows:
1) The data of the optical density (expressed as Attenuance) of the video image of rice grain was analyzed through slice filter of the Image Data Processing System.
2) Attenuance of the basal side of cracked rice grain with one fissure was higher than that of the apical side under oblique illumination, when the illumination lamp was set to the apical side of the sample.
3) The image of cracked rice grain with one fissure in our photograph (Fig. 6) was divided into two parts by the fissure line, when it was processed through slice filter of optical density. The basal side of the grain was indicated with red, and the apical side was indicated with white. As for the grain with two fissures, the processed image of the cracked grain was divided into three parts and was variegated with white, blue and red. The processed image of the grain with three fissures was variegated with white, blue, red and light green.
4) Small crack of rice grain could also be detected.
5) In this method the optimum angle of illumination to rice grain was 20° on the horizontal level of the sample holder. The direction of oblique ray was parallel to the longitudinal line of rice grain.
6) Cracked grains of long grain rice and sakamai or rice for sake-brewing showed a different pattern from short grains of nonglutinous rice.
7) Cracks of unhusked rice grain and glutinous rice grain could not be detected in this experiment.