| 摘要 |
PURPOSE:To shield a pattern excepting for a desired pattern exactly and to enable the exact masking of a color separating board in a short time by executing linear approximation and circular arc approximation for the contour line of the desired pattern from the image information of the color separating board and preparing a mask according to the result. CONSTITUTION:The output of a planar scanner 1 to read the image information of the color separating board is supplied to a binary image preparation part 2, the output of the binary image preparation part 2 is supplied to a contour preparation part 4, and the output of the contour preparation part 4 is supplied to a cutting plotter 5. Whether a point on an image is a point in the pattern is decided corresponding to whether the difference of brightness or hue between the designated point and each point on the image is larger than a prescribed value or not. As the reference of the judgment, the prescribed value is made variable corresponding to conditions. The contour preparation part 4 approximately transforms the contour line of a binary image prepared by the binary image preparation part 2 into a linear vector, further extracts the part of a sharp angle, extracts the part of a curve in the contour line transformed into the linear vector as well, and transforms it into a circular arc. |
