Image processing apparatus, image processing method, and storage medium therefor
AssigneeMurata Kikai Kabushiki Kaisha
InventorKatsushi Minamino
Life of this patent
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Abstract
ROM stores an 8×8 base matrix of 64 sequential threshold values (1-64), hexadecimal data for a specified pattern to be rendered on an output image, and a threshold address table in which the thresholds of the base matrix are arranged in ascending order of threshold value. The MPU generates a second threshold matrix used to render the specified pattern when the matrix is used by dithering unit to dither a source image having a wide range of gray-scale levels.
Claims9
An image processing apparatus that performs pseudo half-tone processing, the apparatus comprising:
- a storage unit that stores a base matrix and font pattern data for a specified pattern;
- means for setting initial threshold values for a source image pattern, a shadow pattern added to the source image pattern, and a background pattern, respectively, based on font data pattern;
- a threshold matrix generating unit that generates a threshold matrix capable of rendering the specified pattern in an output image over a wide range of gray-scale levels based on the base matrix and the font pattern data, and
- means for reassigning the threshold values for a source image pattern, a shadow pattern added to the source image pattern, and a background pattern, respectively, based on a base matrix.
An image processing method for use in an image processing apparatus adapted to perform a pseudo half-tone processing, the method comprising the steps of:
- setting initial threshold values for a source image pattern, a shadow pattern added to the source image pattern, and a background pattern, respectively, based on font data pattern;
- and
- reassigning the threshold values for a source image pattern, a shadow pattern added to the source image pattern, and a background pattern, respectively, based on a base matrix.
An image processing method for use in an apparatus adapted to perform a pseudo half tone processing, comprising the steps of:
- setting initial threshold values for a source image pattern, a shadow pattern attached to the source image pattern, and a background pattern, respectively, based on font data pattern;
- retrieving address data sequentially from a threshold address table;
- and
- reassigning the threshold values for a source image pattern, a shadow pattern attached to the source image pattern, and a background pattern, respectively, based on the address data.
Dependencies are inferred from the claim text.