Color image processing apparatus which performs different image processings depending on region of color image
US6731400B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1997 |
| Grant date | May 4, 2004 |
| Priority date | — |
| Expiry date | Oct 29, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K15/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A data processing part in a printer controller performs multivalued dither processing whereby image data is processed for images of characters and thin lines with a high definition, and for pictures with a high color gradation, and the image quality deterioration at the boundary region between an edge region and a non-edge region can be avoided. The data processing part performs discrimination of an edge region, a non-edge region, and a boundary region between the edge and non-edge regions. Furthermore, the data processing part performs multivalued dither processing by using a prepared dot distribution type dither matrix for the edge region, a prepared dot concentration type dither matrix for the non-edge region and a prepared dot distribution and concentration mixing type dither matrix for the boundary region. Furthermore, the amount of image data to be processed is reduced by dividing an image frame into a plurality of pixel blocks and expressing an image of each pixel block with a few of approximate color data and approximate color arrangement data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.