Image processing apparatus, image processing method, and computer program product

An image processing method implemented in an image processing apparatus, comprising:

• determining, with respect to each drawing object in input image data, whether the drawing object includes a color character group of a single or more characters by making use of a type and color information of the drawing object;
• extracting, when the drawing object is determined to include the color character group, a background area on which the color character group is formed in the drawing object for each color character group;
• first-generating that includes receiving specification of a main color as a printing color and specification of a color expression color, and,
• when the drawing object is determined not to include the color character group, generating monochromatic image data by performing monochromatic conversion of the input image data with a predetermined luminance value, and
• when the drawing object is determined to include the color character group, generating monochromatic image data by performing monochromatic conversion of the input image data with minimum luminance of the main color;
• second-generating that includes obtaining, when the drawing object is determined to include the color character group, a hue of the color character group and, according to the hue, generating pattern image data to be added to the background area of post-monochromatic-conversion color character group;
• and
• synthesizing the monochromatic image data and the pattern image data.

A computer program product comprising a non-transitory computer-usable medium having computer-readable program codes embodied in the medium for an image processing method implemented in an image processing apparatus, the program codes when executed causing a computer to execute:

• determining, with respect to each drawing object in input image data, whether the drawing object includes a color character group of a single or more characters by making use of a type and color information of the drawing object;
• extracting, when the drawing object is determined to include the color character group, a background area on which the color character group is formed in the drawing object for each color character group;
• first-generating that includes receiving specification of a main color as a printing color and specification of a color expression color, and,
• when the drawing object is determined not to include the color character group, generating monochromatic image data by performing monochromatic conversion of the input image data with a predetermined luminance value, and
• when the drawing object is determined to include the color character group, generating monochromatic image data by performing monochromatic conversion of the input image data with minimum luminance of the main color;
• second-generating that includes obtaining, when the drawing object is determined to include the color character group, a hue of the color character group and, according to the hue, generating pattern image data to be added to the background area of post-monochromatic-conversion color character group;
• and
• synthesizing the monochromatic image data and the pattern image data.