Image processing apparatus
US6775027B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 1, 1999 |
| Grant date | Aug 10, 2004 |
| Priority date | — |
| Expiry date | Dec 1, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/40087
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An error adding portion adds together input multi-tone image data and peripheral error information. An adding/subtracting portion adds to or subtracts from multi-tone image data calculated by the error adding portion, a random number in a matrix prepared for each set of pixels of the input multi-tone image data. A quantizing portion quantizes multi-tone image data calculated by the adding/subtracting portion into image data, the number of bits of which image data being smaller than the number of bits of the multi-tone image data calculated by the adding/subtracting portion. An error calculating portion calculates an error based on the multi-tone image data calculated by the error adding portion and the image data quantized by the quantizing portion. An error storing portion stores the error calculated by the error calculating portion for each peripheral pixel. An error operation portion calculates peripheral error information based on the error stored by the error storing portion for each peripheral pixel, and provides the peripheral error information to the error adding portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.