Method and device for color data generation
AssigneeBrother Kogyo Kabushiki Kaisha
InventorTatsuya Sato
Life of this patent
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Abstract
A device and method is provided for generating color data for image formation by converting C, M, Y, data into C, M, Y, K data. The minimum value of the three color values of C, M, Y is selected and, depending on the color of the minimum value, a black data generating table is selected to generate a value for the black color K. The black data generating tables have different black data conversion characteristics from one another and are associated with the three colors of cyan, magenta, and yellow, respectively.
Claims24
A method of generating color data for image formation in a color image forming device by converting data of color values for three colors of cyan, magenta, and yellow, representing a color image to be formed, into data of color values for four colors of cyan, magenta, yellow, and black, the method comprising:
- preparing a plurality of black data generating tables which have different black data conversion characteristics from one another;
- receiving a set of color data including color values for three colors of cyan, magenta, and yellow;
- extracting a minimum value among the three color values in the received set of color data;
- selecting only one black data generating table dependently on color of the extracted minimum value irrespective of whether the three color values in the received set of color data are different from one another;
- and
- generating a value for black using the selected black data generating table and based on the extracted minimum value.
A color data generating device, provided in a color image forming device, for generating color data for image formation by converting data of color values for three colors of cyan, magenta, and yellow, representing a color image to be formed, into data of color values for four colors of cyan, magenta, yellow, and black, the device comprising:
- a table storage portion storing a plurality of black data generating tables which have different black data conversion characteristics from one another;
- an input portion receiving a set of color data including color values for three colors of cyan, magenta, and yellow;
- an extracting portion extracting a minimum value among the three color values in the received set of color data;
- a table selecting portion selecting only one black data generating table dependently on color of the extracted minimum value irrespective of whether the three color values in the received set of color data are different from one another;
- and
- a black generating portion generating a value for black using the selected black data generating table and based on the extracted minimum value.
A method of generating color data for image formation in a color image forming device by converting data of color values for three colors of cyan, magenta, and yellow, representing a color image to be formed, into data of color values for four colors of cyan, magenta, yellow, and black, the method comprising:
- preparing a plurality of black data generating tables which have different black data conversion characteristics from one another;
- receiving a set of color data including color values for three colors of cyan, magenta, and yellow;
- extracting a minimum value among the three color values in the received set of color data;
- selecting only one black data generating table dependently on color of the extracted minimum value irrespective of whether the three color values in the received set of color data are different from one another;
- generating a value for black using the selected black data generating table and based on the extracted minimum value;
- and
- correcting the color values for cyan, magenta, and yellow in the received color data set by subtracting the generated value for black from the three values for cyan, magenta, and yellow, respectively.
A color data generating device, provided in a color image forming device, for generating color data for image formation by converting data of color values for three colors of cyan, magenta, and yellow, representing a color image to be formed, into data of color values for four colors of cyan, magenta, yellow, and black, the device comprising:
- a table storage portion storing a plurality of black data generating tables which have different black data conversion characteristics from one another;
- an input portion receiving a set of color data including color values for three colors of cyan, magenta, and yellow;
- an extracting portion extracting a minimum value among the three color values in the received set of color data;
- a table selecting portion selecting only one black data generating table dependently on color of the extracted minimum value irrespective of whether the three color values in the received set of color data are different from one another;
- a black generating portion generating a value for black using the selected black data generating table and based on the extracted minimum value;
- and
- a correcting portion correcting the color values for cyan, magenta, and yellow in the received color data set by subtracting the generated value for black from the three values for cyan, magenta, and yellow, respectively.
Dependencies are inferred from the claim text.