Controlling black levels using a three dimensional intermediate color space

A method comprising:

• receiving, by operation of a computer, an input color value of a source color space for conversion to a destination color space, the destination color space having more color components than the source color space;
• and
• converting, by operation of a computer, the input color value to a preferred color value in the destination color space using a conversion process for converting color values in the source color space to the destination color space, the conversion process determined by:
• identifying a plurality of preferred color values in the destination color space, each of the plurality of preferred color values being one of a set of colorimetrically equivalent color values;
• defining intermediate color values in an intermediate color space, the intermediate color values corresponding to the plurality of preferred color values, the intermediate color space having a number of color components that is equal to a number of color components of the source color space;
• identifying a known mapping from the destination color space to the source color space, wherein the source color space differs from the intermediate color space;
• and
• using the intermediate color values and the known mapping to determine the conversion process for converting color values in the source color space to color values in the destination color space.

A computer program product, encoded on a non-transitory computer-readable medium, operable to cause data processing apparatus to perform operations comprising:

• receiving an input color value of a source color space for conversion to a destination color space, the destination color space having more color components than the source color space, the destination color space having multiple sets of equivalent color values, each of the multiple sets having a preferred color value;
• receiving a conversion process for converting color values in the source color space to the destination color space, the conversion process determined by:
• identifying a plurality of preferred color values in the destination color space, each of the plurality of preferred color values being one of a set of colorimetrically equivalent color values;
• defining intermediate color values in an intermediate color space, the intermediate color values corresponding to the plurality of preferred color values, the intermediate color space having a number of color components that is equal to a number of color components of the source color space;
• identifying a known mapping from the destination color space to the source color space, wherein the source color space differs from the intermediate color space;
• and
• using the intermediate color values and the known mapping to determine the conversion process for converting color values in the source color space to color values in the destination color space;
• and
• converting the input color value to a preferred color value in the destination color space using the conversion process.

A system comprising:

• a memory operable to store a first electronic document comprising a plurality of color values in a first color space and a second electronic document comprising a plurality of color values in a second color space;
• and
• one or more processors communicatively coupled to the memory operable to perform operations comprising:
• identifying a plurality of preferred color values in a destination color space, each preferred color value being one of a set of colorimetrically equivalent color values, the destination color space having color values defined by a particular number of color components;
• defining intermediate color values in an intermediate color space, the intermediate color values corresponding to the plurality of preferred color values, the intermediate color space having a number of color components that is less than the particular number of color components of the destination color space;
• identifying a known mapping from the destination color space to a source color space, wherein the source color space differs from the intermediate color space;
• and
• using the intermediate color values and the known mapping to determine a conversion process for converting source color values to preferred color values in the destination color space.