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:
Feb. 10, 2004
Filed:
Jan. 24, 2000
Gordon Wesley Braudaway, Yorktown Heights, NY (US);
Albert Nessim Cazes, Mount Kisco, NY (US);
James Edward Christensen, Cortlandt Manor, NY (US);
Michael James Cordes, Newburgh, NY (US);
Donald Michael DeCain, New York, NY (US);
Shui-Chih Alan Lien, Briarcliff Manor, NY (US);
Frederick Cole Mintzer, Shrub Oak, NY (US);
Steven Lorenz Wright, Cortlandt Manor, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The present invention provides methods and apparatus for the color calibration of displays. These methods are particularly useful for displays having properties different than those associated with cathode ray tubes (CRT). Some displays, for example liquid crystal displays (LCD), have a high luminance black, the chromas of their primaries are not independent of their luminance levels, the intensities of their primaries are not strictly monotonically increasing with respect to their RGB levels, the color additivity of their subpixels is affected by crosstalk or leakage and their color measurements are dependent on the view angle of the observer. Therefore, the usage of CRT methods is deficient for such displays. The methods and apparatus of the present invention overcome several deficiencies generally found in non-CRT display devices by employing techniques associated with the use of restricted ranges for the primaries, subtracting the color black from all color measurements, forming a modified display matrix and/or creating tables which correct errors due to the non-linearities or color leakages of these display devices. These enable images to be processed using algorithms of different complexity and precision.