| 摘要 |
PROBLEM TO BE SOLVED: To extract an invalid zone for improving a rate to make judgement about the existence or non-existence of the pieces by preparing a histogram on the basis of an inter-image computation result between a label image and an edge extracted image, and applying a threshold value to the histogram. SOLUTION: An edge extracted image is generated from the images of pieces on a Japanese chess board picked up via a CCD camera 1, using the first luminance value of square lines on the board, a character on each piece and an obstruction such as hands, and the second luminance value of the bare surface of the board. Then, the preset inter-image calculation is made between a label image at a position corresponding to a plurality of positions on square lines in the edge extracted image, and the edge extracted image, thereby obtaining the image where the luminance value of only a picture element having the first luminance value is converted to the luminance value of a corresponding label in such zones as corresponding to each label on the edge extracted image. Also, a histogram is prepared to show the frequency of picture elements for the luminance value, based on the image so obtained, and a square at a label position corresponding to a luminance value equal to or less than a threshold value is extracted as an invalid zone. |
