Ordered dither image rendering with non-linear luminance distribution palette
US5398120A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 1993 |
| Grant date | Mar 14, 1995 |
| Priority date | — |
| Expiry date | Dec 16, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/6058
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A high color resolution image is accurately approximated with a low resolution image through ordered dithering to colors of a displayable color palette. The colors of the displayable color palette are located at points of a grid aligned with three orthogonal axes in a three dimensional color model, including a luminance axis between black and white. The grid points are defined by the intersections of three sets of parallel planes, each set being perpendicular to one of the three axes. The set of planes perpendicular to the luminance axis are spaced nonuniformly, preferably according to a cubic model. The ordered dithering maps the true color of a pixel in the image to the color in the displayable palette at one of eight adjacent grid points. When ordered dithering of a pixel's true color would map the true color to a grid point outside the color gamut, the pixel is instead mapped to the nearest color on the color gamut's border to the grid point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.