Patent ID: 8040563
Filing Date: 2011-10-18
Classification: H04N

Abstract:
1. A method for printing an image by using ink of at least one achromatic color and at least three chromatic colors based on RGB image data obtained from a printed image, the method comprising: setting a plurality of first lattice points in an RGB color solid defined by RGB components of the RGB image data; storing a first table indicating a relationship between a color defined by each of the first lattice points and amounts of the ink of the achromatic color and the ink of the chromatic colors; storing a second table indicating a relationship between one of a plurality of brightness values and an amount of the ink of achromatic color for representing the one of the brightness values; storing information indicating a relationship between the brightness values and some of the first lattice points located at a ridge area including a ridge line of the RGB color solid at which two of the RGB components take either maximum values or minimum values thereof; generating a third table in which the second table is embedded in the first table based on the information; extracting a character area in which a character is printed from the printed image; converting first RGB components of the image data corresponding to the extracted character area into the RGB components defined by the some of the lattice points based on brightness values of the RGB components of the image data, thereby generating modified image data; converting the RGB components of the modified image data into amounts of the ink of a chromatic color and the ink of chromatic colors based on the third table; and printing the image in accordance with the converted amounts of the ink of achromatic color and the ink of chromatic colors.