Method and Apparatus for Correcting Geometric Errors While Preserving Defined Information
AssigneeHeidelberger Drickmaschinen AG
InventorEBERHARD REDMER
Life of this patent
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Abstract
A method and an apparatus are provided for correcting geometric errors during a transfer of a printing image to a printing material. For the purpose of correction, a raster bitmap is fed to a matrix manipulation device, which distorts the raster bitmap. The problem with the distortion is that areas such as edge marks are also distorted. In order to avoid those undesired distortions, a protected area determining device for determining a protected area within the raster bitmap and/or the master print, and a protective element for preserving the content of a protected area within a raster bitmap, are provided.
Claims14
A method for correcting geometric errors during a transfer of a printing image to a printing material, the method comprising the following steps:
- setting up at least one master print on which the printing image is based;
- screening the master print and producing at least one raster bitmap in the form of a matrix with m lines and n columns having elements containing information about a color to be printed;
- manipulating the raster bitmap by matrix manipulation to compensate for geometric distortions of the printed image on the printing material;
- defining protected areas in at least one of the master print or the raster bitmap;
- and
- maintaining at least one of all points or all elements within the protected area unchanged after the matrix manipulations have been carried out.
An apparatus for correcting geometric errors during a transfer of a printing image to a printing material, the apparatus comprising:
- a raster image processor for screening master prints and producing raster bitmaps;
- a matrix manipulation device for manipulating a raster bitmap present in the form of a matrix with m lines and n columns;
- and
- a matrix protection device including a protected area determining device for determining a protected area within at least one of the raster bitmap or a master print and a protective element for preserving a content of a protected area within a raster bitmap.
Dependencies are inferred from the claim text.