Method and apparatus for the analysis of color casts in color originals
US5420704A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 1994 |
| Grant date | May 30, 1995 |
| Priority date | — |
| Expiry date | Sep 19, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/6077
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for the analysis of a color cast in a color original to be reproduced, by evaluating color values acquired by point-by-point and line-by-line, trichromatic scanning with an image processing input device. For acquiring a color cast in the color original, a region of high luminance values (light image region) and/or a region of low luminance values (dark image region) of the luminance component L* of the color values L*, a*, b* in the color original to be analyzed is/are subdivided into at least one luminance region. The value of a potentially existing color cast in the luminance region is identified by averaging the color components a*, b* of the color values L*, a*, b* in the luminance region. The color cast value to be utilized for the evaluation of the color cast analysis is formed by selection and/or combination of color cast values identified for individual luminance regions. In addition, at least one luminance region is demarcated to form an analysis region in view of the chrominance c* by forming chrominance regions around the gray axis of the color space, whereby the demarcated analysis region is then utilized for calculating a potential color cast.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.