The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 02, 1995
Filed:
Aug. 02, 1993
David E Holland, Granada Hills, CA (US);
Gavin W Schutz, Glendale, CA (US);
Image Transform Inc., North Hollywood, CA (US);
Abstract
An improved method and apparatus for color correction normalizes two of the three color signals as a function of the third. In the preferred embodiment, an image comprising red, green and blue (RGB) signals are converted to a luminance Y signal, a saturation signal and a hue signal. The luminance and saturation signals are normalized as a function of hue. In the most preferred embodiment, for all fully saturated colors, the luminance values are normalized to a value of 0.5, and the saturation values to unity for all values of hue. The normalized values of saturation and luminance are utilized with the hue value in a secondary color corrector. The color corrected values of saturation and luminance are denormalized as a function of color corrected hue. Optionally, the color corrected luminance, saturation and hue may be converted to RGB signals for output. In one aspect of this invention, the normalized luminance signal is not used for relatively small values of saturation. In another aspect of this invention, multiple color correction regions are provided on an image. Overlapping regions are assigned priorities.