Karl Henry Lang

US Patent:

6933967, Aug 23, 2005

Filed:

Sep 9, 2003

Appl. No.:

10/659447

Inventors:

Paul David Doyle - San Marcos CA, US
Rafael Calderon - San Diego CA, US
Matthew C. Boyko - San Francisco CA, US
Roy Bragadeste - Round Rock TX, US
Don Moore - Renton WA, US
Mike McKay - Shoreline WA, US
Karl Lang - Madison WI, US
Andrew Bryant - San Diego CA, US
Martin Kolinek - Bellevue WA, US

Assignee:

Sony Corporation - Tokyo
Sony Electronics Inc. - Park Ridge NJ

International Classification:

H04N017/02

US Classification:

348189, 348191

Abstract:

A color calibration system includes a visual display terminal (VDT), a color calibration sensor optically coupled to the VDT, and a computer processing unit (CPU) electrically coupled to the VDT and the color calibration sensor. The VDT has a display screen and a plurality of color channels, each color channel having an intensity input, a bias input, and a gain input. The VDT produces an image on the display screen responsive to the intensity input. The color calibration sensor provides values responsive to the chromaticity and luminance of a test patch portion of the image on the display screen. The CPU performs calibration of the VDT including setting the bias of each color channel to reduce the difference between a target black point and the test patch with the intensity input at a minimum value for each color channel.

US Patent:

8547580, Oct 1, 2013

Filed:

Oct 15, 2010

Appl. No.:

12/905957

Inventors:

Nancy Wang - Sunnyvale CA, US
Karl Lang - Madison WI, US

Assignee:

Apple Inc. - Cupertino CA

International Classification:

G06K 5/00

US Classification:

358 115, 358 19

Abstract:

Print performance is evaluated by printing a diagnostic image comprising color patches. Colorant usage in the printed image is measured by, for instance, scanning each patch. Measured color values are then compared to target color values. Based on the comparison, groups of patches whose color values vary significantly from expectations are identified. Variant groups are then analyzed to identify, in addition to color quality control problems, spatial problems that affect only a localized area of a printed page. Such spatial problems may include, for example, problems with contrast or streaks. A heat map illustrating the differences may be generated to help an operator visualize the spatial problem. A template for the diagnostic image may be selected from a plurality of randomly generated diagnostic targets based on total colorant usage for at least one colorant in each column of color patches. Certain patches may be predefined across for each candidate target.