Patent 7968814 was granted and assigned to Satake Corporation on June, 2011 by the United States Patent and Trademark Office.
A grain images obtained by CCD line sensors are processed by binarization processing to obtain contour images of grains and images of colored portions in the grains. The images are displayed on a monitor screen of an operating panel 30. The contour images and the images of the colored portions are displayed in a superposed state. Box frames generated by a highlight display circuit in control means 12 are simultaneously displayed by being superposed on the contour images having defective portions, thus producing a highlight display of defective grains. The defective grains include a grain having a light colored portion and a grain having a dark colored portion.