Patent ID: 7639401

Claim:
A method of correcting colors input to an output device, comprising: adjusting, based on a user's input, an output device to correctly display, at a predefined known luminance level, an input target having a predefined calibration input value corresponding to the predefined known luminance level; rendering, on the output device subsequently to the adjusting, a target of patches, each patch in the target of patches having a respective known input value, the target of patches comprising: at least one base patch having the predefined calibration input value, thereby resulting in the at least one base patch being displayed by the rendering on the output device with the predefined known luminance level; and a plurality of calibration patches comprising separate patches each having a respective input value corresponding to a different known respective luminance value, wherein patches within the plurality of calibration patches are displayed by the rendering on the output device with respective uncalibrated luminance levels that are different from the predefined known luminance level; capturing, with a common digital camera, a captured an image of a rendering of the target of patches produced by the rendering; extracting camera signals from the captured image for each of the plurality of calibration patches and the at least one base patch; deriving a tone response calibration for the output device based upon a measured relationship between the camera signals extracted for each of the plurality of calibration patches and their respective input values relative to the camera signals extracted for the at least one base patch and the predefined calibration input value; and applying the derived tone response calibration to the output device so as to provide corrected colors therefrom.