Rendering images utilizing adaptive error diffusion
US6937365B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 2001 |
| Grant date | Aug 30, 2005 |
| Priority date | — |
| Expiry date | Aug 19, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4053
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An adaptive halftoning method where the difference between a digital image and a filtered digital image is introduced into the system on a pixel by pixel basis is disclosed. In this method, each input difference pixel has a corresponding error value of the previous pixel added to the input value at a summing node, resulting in modified image difference data; the modified image difference data is passed to a threshold comparator where the modified image difference data is compared to a threshold value, the threshold value varying according to the properties of the digital image, to determine the appropriate output level; the output level is subtracted from the modified image difference value to produce the input to an error filter; the output of the error filter is multiplied by an adaptation coefficient, where the adaptation coefficient varies according to the properties of the digital image, to generate the error level for the subsequent input pixel; and, the cyclical processing of pixels is continued until the end of the input data is reached.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.