HSL corrections in CMY color space
US5612795A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 8, 1994 |
| Grant date | Mar 18, 1997 |
| Priority date | — |
| Expiry date | Sep 8, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/6011
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Original CMYK printing colors of an original image are corrected, and then the corrected printing colors are converted by color computer to RGB video signals for display on a color video display. The desired corrections are defined in terms of HSL (hue, saturation, luminance) changes. The original CMY printing colors are transformed to the corrected or new CMY printing colors by use of the HSL changes without a color space translation. The HSL changes are directly applied to the original CMY printing colors to arrive at the new CMY printing colors. The transformation comprises using a gray line representing an absence of color and changing luminance within the original CMYK printing color space and executing the HSL changes with respect to the gray line. The HSL changes are clamped within the color space so that no new CMYK printing colors result which are unprintable outside the color space.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.