Color calibration method and apparatus

A method, comprising:

• depositing a first quantity of a first colorant, corresponding to a first color value, and a second quantity of a second colorant corresponding to a second color value on a region of media, with the first color value included in a plurality of color values;
• determining a value related to a hue of the region;
• determining a difference between the value related to the hue of the region and a predetermined value;
• and
• changing one of a plurality of first colorant quantity values, corresponding to the first quantity of the first colorant and with the plurality of first colorant quantity values corresponding to the plurality of color values
• by dividing the difference by the predetermined value to form a fraction, multiplying the fraction by the one of the plurality of first colorant quantity values to form a result and adding the result to the one of the plurality of first colorant quantity values.

An apparatus, comprising:

• a spectral measurement device configured to generate output corresponding to a spectral content of light reflected from a region on media formed by depositing a first quantity of a first colorant and a second quantity of a second colorant onto the media;
• a memory to store a first plurality of color values, a corresponding second plurality of color values, and a plurality of first colorant quantity values corresponding to the second plurality of color values;
• and
• a processing device coupled to the memory and arranged to receive the output from the spectral measurement device and configured to determine a value related to a hue of the region using the output, configured to determine a difference between the value related to the hue of the region and a predetermined value, and configured to change at least one of the second plurality of color values according to the difference.

An apparatus, comprising:

• a spectral measurement device configured to generate output corresponding to a spectral content of light reflected from a region on media formed by depositing a first quantity of a first colorant and a second quantity of a second colorant onto the media;
• a memory to store a first plurality of color values, a corresponding second plurality of color values, and a plurality of first colorant quantity values corresponding to the second plurality of color values;
• and
• a processing device coupled to the memory and arranged to receive the output from the spectral measurement device and configured to determine a value related to a hue of the region using the output, configured to determine a difference between the value related to the hue of the region and a predetermined value with the processing device including a configuration to change each one of the plurality of first colorant quantity values by dividing the difference by the value related to the hue to form a fraction, multiplying the fraction by the one of the plurality of first colorant quantity values to form a result and adding the result to the one of the plurality of first colorant quantity values to change the association between the plurality of color values and the plurality of first colorant quantity values.

A calibration system, comprising:

• means for measuring tristimulus values of an area of media having deposited a first quantity of a first colorant corresponding to a first color value and having deposited a second quantity of a second colorant corresponding to a second color value;
• means for determining a first set of values representing a color of the area using the tristimulus values;
• means for determining a difference between the first set of values and a second set of values related to a hue intended to result from the first colorant and the second colorant;
• a memory to store a third set of values each of which represent a quantity of the first colorant, including the first quantity of the first colorant and correspond to one of a fourth set of color values including the first color value;
• and
• means for changing an association between the third set of values and the fourth set of values by changing a fifth set of values, corresponding to the third set of values and corresponding to the fourth set of values, according to the difference.