| 摘要 |
PURPOSE:To detect only foreign matter by removing the diagonal component or the corner part of a fixed pattern which cannot be removed in a filtering processing by the use of previously calculated data. CONSTITUTION:The picture of a part of an object 11 to be detected is photographed by a television camera 14, an video signal inputted to a arithmetic unit 15 is recorded on a picture memory 22 through an A/D converting part 21. An arithmetic part 25 carries out the filtering processing of a difference operation to this digital picture to remove horizontal and vertical differential components in the picture. The sum of respective picture elements in X and Y directions is taken with respect to the filtering picture to check to the data of an interval between the grid points of the previously examined fixed pattern and decide the position of the grid point and the differential component of that point is removed. Thereafter, the differential component which is left is detected and the area of an original picture is divided on that part, thereby, the foreign matter is detected. |
