Method of and apparatus for transforming color image data on the basis of an isotropic and uniform colorimetric space
US4839721A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 1984 |
| Grant date | Jun 13, 1989 |
| Priority date | — |
| Expiry date | Aug 28, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/6011
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A color transform enables color-image information to be recorded, displayed and otherwise processed with exacting control of color relative to a selected display. Apparatus implementing the transform enables a single-exposure photographic print of image information produced in pre-press equipment to predict with accuracy an ink-on-paper print of that information. Color-image information is transformed with a technique that produces output information for each output color component or other parameter at each point in response to up to all input parameters at that point. The technique includes scaling, normalizing and linearizing steps, and may include selecting a uniform color space for mapping the color response of the object (film) medium with the color response of the reference (print) medium. The output information may include approximate transform values and finalizing values. The technique can be implemented for real-time conversion with look-up tables storing approximate transform values and storing interpolation factors, including gradient values, for computing finalizing values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.