Pseudo halftone image processing using a threshold matrix to form dots not rotational symmetric on a 90 degree basis
AssigneeCanon Kabushiki Kaisha
InventorHirokazu Tamura
Life of this patent
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Abstract
An image processing apparatus which performs image processing for print processing, including: a pseudo halftone processing unit configured to perform pseudo halftone processing by dithering with respect to an input image, and generate a halftone image constituted by plural dots, and a threshold matrix holding unit configured to hold a threshold matrix used for the pseudo halftone processing, wherein in the threshold matrix, thresholds are arranged such that the halftone image has a density region in which dots to be formed depending on a density of the input image are not rotational symmetric on a 90° basis, and orientations of the dots differ from each other in the density region.
Claims15
An image processing apparatus which performs image processing for print processing, comprising:
- a pseudo halftone processing unit configured to perform pseudo halftone processing by dithering with respect to an input image, and generate a halftone image constituted by plural dots, and
- a threshold matrix holding unit configured to hold a threshold matrix used for the pseudo halftone processing,
- wherein
- in the threshold matrix, thresholds are arranged such that the halftone image has a density region in which dots to be formed depending on a density of the input image are not rotational symmetric on a 90° basis, and orientations of the dots differ from each other in the density region.
A method for performing pseudo halftone processing by dithering with respect to an input image, and generating a halftone image constituted by plural dots, wherein
- in a threshold matrix used for the pseudo halftone processing, thresholds are arranged such that the halftone image has a density region in which dots to be formed depending on a density of the input image are not rotational symmetric on a 90° basis, and orientations of the dots differ from each other in the density region.
A non-transitory computer readable storage medium storing a program for causing a computer to perform a method for controlling an image processing apparatus which performs pseudo halftone processing by dithering with respect to an input image, and generates a halftone image constituted by plural dots, the control method comprising the steps of;
- in a threshold matrix used for the pseudo halftone processing, thresholds are arranged such that the halftone image has a density region in which dots to be formed depending on a density of the input image are not rotational symmetric on a 90° basis, and orientations of the dots differ from each other in the density region.
Dependencies are inferred from the claim text.