Method and apparatus for adaptive dithering
US5712657A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1995 |
| Grant date | Jan 27, 1998 |
| Priority date | — |
| Expiry date | Mar 28, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G3/2051
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An adaptive dithering apparatus analyzes an input video signal as a function of available primary shades and produces a select signal whose value is a function of the desired shade represented by the input video signal and of the available primary shades. A combiner combines the input video signal with a selected one of a plurality of dither signals to generate a dithered input video signal. The one dither signal is selected under the control of the select signal. Finally, an adjustor receives the dithered input video signal, the available shade signal, and the select signal and, under the control of the select signal, adjusts the dithered input video signal to have a value equal to one of the available primary shades. Thus, an input video signal may be dithered with a dither signal that is optimized for dithering an input signal that falls into a particular range of desired shades. That is, a different dither signal may be employed for each possible spacing of adjacent available primary shades. As a result, an overall quantizing transfer function can be achieved which is, on average, linear for all values of the input video signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.