Method and apparatus for determining register differences from a multi-color printed image
First Claim
1. A method of determining register differences in a multi-color printed image formed of a plurality of superimposed single-color printed images, the method comprising the steps of:
- scanning at least a part of the multi-color printed image with a color video camera to produce an enlarged electronic video image of a size adequate to resolve individual dots making up the image,processing the video image to derive a plurality of single-color images and storing the single-color images in respective color memories,selecting a register-checking location which includes a contour in the printed image comprising at least two superimposed single-colors,determining separation contours in the respective single-color images from the information stored in the respective color memories at the register-checking location, anddetermining offsets between the separation contours as a measure of register differences between the single color images.
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Accused Products
Abstract
A system and method for determining register differences between the images making up a multi-color printed image. A color video camera with macro optics scans at least a part of the image. The video image is processed to derive a plurality of single-color images, information from which is stored in respective single color memories. A register-checking location is selected having a contour in the printed image which has at least two superimposed single colors. The information in the color memories is processed to determine separation contours for the respective colors. Offsets are determined for the contours in the respective image memories as a measure of register differences between the images.
85 Citations
20 Claims
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1. A method of determining register differences in a multi-color printed image formed of a plurality of superimposed single-color printed images, the method comprising the steps of:
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scanning at least a part of the multi-color printed image with a color video camera to produce an enlarged electronic video image of a size adequate to resolve individual dots making up the image, processing the video image to derive a plurality of single-color images and storing the single-color images in respective color memories, selecting a register-checking location which includes a contour in the printed image comprising at least two superimposed single-colors, determining separation contours in the respective single-color images from the information stored in the respective color memories at the register-checking location, and determining offsets between the separation contours as a measure of register differences between the single color images. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A system for determining register differences in a multi-color printed image formed of a plurality of superimposed single-color printed images, the system comprising, in combination:
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a color video camera having a macro-optical system for scanning at least a part of the multi-color printed image and producing an enlarged electronic image of a size adequate to resolve individual dots making up the printed image, video converter means for deriving a plurality of single-color images and storing the single-color images in respective color memories, means for defining a register-checking location in of the printed image which include a contour comprising at least two superimposed single-colors, image processing means for determining contours in the respective single-color images from the information stored in the respective color memories at the register-checking location, the image processing means further including means for determining offsets between the separation contours of the respective single color images as a measure of register differences between said single color images. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification