Image error diffusion device with noise superposition
US6847732B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 8, 2000 |
| Grant date | Jan 25, 2005 |
| Priority date | — |
| Expiry date | Jul 2, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/10024
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Disadvantages of conventional image processing devices using a vector error diffusion method include the generation of periodic texture noise of specific selected colors, resulting in marked reduction of graininess. A noise overlay unit is provided as a front stage of an error adding unit for adding error to input image data. If noise is superimposed on the L*a*b* color space or L*C*h color space, quantitative image evaluation matching human perception is possible, and overlay noise can be effectively optimized. If the total sum of the absolute amount of overlay noise is zero, the color tone of the entire image can be maintained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.