Method and apparatus for adaptive color characterization and calibration

A method of calibrating a desk top computer color device, comprising the steps of:

• (a) controlling the color device to produce color characterization curves of a color response of the device;
• and
• (b) adaptively producing color balanced calibration tables from the characterization curves, step (b) comprising:
• (b1) determining scaling constants;
• (b2) normalizing the characterization curves for a maximum device dynamic range compensating for saturation;
• (b3) determining a most negative normalized response;
• (b4) determining color balance constants from the most negative normalized response;
• (b5) scaling aim curves using the color balance constants;
• and
• (b6) creating the calibration tables using the scaled aim curves and the normalized characterization curves.

A method of creating one dimensional color calibration tables from response characterization values produced by a color input/output device, comprising the steps of:

• (a) normalizing the characterization values;
• (b) determining white point color balanced aim curves from the characterization values;
• and
• (c) producing the color calibration tables using the balanced aim curves and the characterization values.

An apparatus for color device calibration, comprising:

• intensity measurement means for separately measuring intensity characterization curves of color channels of the color device;
• and
• calibration means for creating calibration curves for producing a white point balanced response by the color device responsive to the characterization curves, said calibration means comprising:
• constant means for determining normalized color balanced scaling constants;
• normalization means for normalizing the characterization curves to a maximum response;
• balance constant means for determining curve balance constants using the scaling constants;
• balance curve scaling means for scaling aim curves with the curve balance constants;
• and
• balanced curve creation means for creating correction tables by transforming the characterization curves using the scaled aim curves.

An apparatus for calibrating a color device, the color device comprising a monitor, printer and scanner, the apparatus comprising:

• an achromatic light sensor separately and achromatically measuring intensity characterization curves of color channels of the color device;
• and
• a computer creating calibration curves for producing a white point balanced response by the color device responsive to the characterization curves, said computer comprising:
• constant means for determining normalized color balanced scaling constants;
• normalization means for normalizing the characterization curves to a maximum response;
• balance constant means for determining curve balance constants using the scaling constants;
• balance curve scaling means for scaling aim curves with the curve balance constants;
• and
• balanced curve creation means for creating correction tables by transforming the characterization curves using the scaled aim curves.