Color data conversion apparatus and method using gamut boundary descriptors

A color data conversion apparatus comprising:

• a converter which converts entered color data to converted color data, the converted color data residing within a gamut defined by a total gamut boundary descriptor (GBD) that covers all gamuts defined by a plurality of K GBDs, and outputs the converted color data;
• a K ratio calculator which calculates a calculated K ratio based on the converted color data,
• wherein the K ratio calculator obtains an initial K ratio which is a K ratio corresponding to a lightness of the entered color data, and acquires the calculated K ratio using the initial K ratio;
• a K ratio adjuster which adjusts the calculated K ratio, based on the plurality of K GBDs, and outputs a final K ratio,
• wherein the K ratio adjuster determines if the entered color data resides within a GBD corresponding to a first K ratio and within a GBD corresponding to a second K ratio that is greater than the first K ratio,
• wherein the K ratio adjuster outputs the calculated K ratio as the final K ratio when the calculated K ratio is greater than the first K ratio and less than the second K ratio,
• wherein the K ratio adjuster outputs the first K ratio as the final K ratio when the calculated K ratio is less than the first K ratio, and
• wherein the K ratio adjuster outputs the second K ratio as the final K ratio when the calculated K ratio is greater than the second K ratio;
• and
• a CMY ratio calculator for calculating C, M, and Y ratios based on the final K ratio.