US 11,247,482 B2Granted

Image processing apparatus, method, and product for reducing color unevenness based on edge information

AssigneeCanon Kabushiki Kaisha

InventorsJunichi Nakagawa, Yumi Yanai

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Abstract

An image processing apparatus includes a processing unit that converts first input image data for a first region and second input image data for a second region to reduce a difference between first region recorded image density and second region recorded image density, and generates dot position data of a dot to be generated in each of the first and second regions based on the dot data after the conversion processing. The acquisition unit acquires edge information indicating a first object pixel edge of an image pixel for the first region and a second object pixel edge of an image pixel for the second region. Based on the acquired edge information, conversion and generation processing are performed in such a manner that a color signal of an edge pixel is increased/reduced to a degree lower than a degree to which a color signal of a non-edge object pixel is increased/reduced.

Claims14

Dependent claims

An image processing apparatus, wherein the image processing apparatus is configured to perform image processing for recording an image in a first region on a recording medium using a first nozzle group including a part of a plurality of nozzles arranged in a nozzle array in which the plurality of nozzles are configured to provide ink, and to perform image processing for recording an image in a second region different from the first region using a second nozzle group including a nozzle different from the part of the plurality of nozzles in the first nozzle group, the image processing apparatus comprising:

a processing unit configured to perform conversion processing to convert first input data of the image to be recorded in the first region and second input data of the image to be recorded in the second region to reduce a difference between a density of the image recorded in the first region using the first nozzle group with respect to an input of a predetermined color signal and a density of the image recorded in the second region using the second nozzle group with respect to the input of the predetermined color signal, and configured to perform generation processing for generating dot data indicating a position of a dot to be generated in each of the first region and the second region based on the dot data after the conversion processing;
and
an acquisition unit configured to acquire edge information indicating a pixel corresponding to a first edge of an object in the image to be recorded in the first region and indicating a pixel corresponding to a second edge of the object in the image to be recorded in the second region,
wherein, based on the acquired edge information, the processing unit performs the conversion processing and the generation processing in such a manner that a color signal of an edge pixel corresponding to an edge is increased/reduced to a degree lower than a degree to which a color signal of a non-edge pixel corresponding to a non-edge of the object is increased/reduced.

1 more element

A method for an image processing apparatus, wherein the image processing apparatus is configured to perform image processing for recording an image in a first region on a recording medium using a first nozzle group including a part of a plurality of nozzles arranged in a nozzle array in which the plurality of nozzles are configured to provide ink, and to perform image processing for recording an image in a second region different from the first region using a second nozzle group including a nozzle different from the part of the plurality of nozzles in the first nozzle group, the method comprising:

performing conversion processing to convert first input data of the image to be recorded in the first region and second input data of the image to be recorded in the second region to reduce a difference between a density of the image recorded in the first region using the first nozzle group with respect to an input of a predetermined color signal and a density of the image recorded in the second region using the second nozzle group with respect to the input of the predetermined color signal, and performing generation processing for generating dot data indicating a position of a dot to be generated in each of the first region and the second region based on the dot data after the conversion processing;
and
acquiring edge information indicating a pixel corresponding to a first edge of an object in the image to be recorded in the first region and indicating a pixel corresponding to a second edge of the object in the image to be recorded in the second region,
wherein, based on the acquired edge information, processing includes performing the conversion processing and performing the generation processing in such a manner that a color signal of an edge pixel corresponding to an edge is increased/reduced to a degree lower than a degree to which a color signal of a non-edge pixel corresponding to a non-edge of the object is increased/reduced.

1 more element

A non-transitory computer-readable storage medium storing a program to cause a computer to perform a method for an image processing apparatus, wherein the image processing apparatus is configured to perform image processing for recording an image in a first region on a recording medium using a first nozzle group including a part of a plurality of nozzles arranged in a nozzle array in which the plurality of nozzles are configured to provide ink, and to perform image processing for recording an image in a second region different from the first region using a second nozzle group including a nozzle different from the part of the plurality of nozzles in the first nozzle group, the method comprising:

performing conversion processing to convert first input data of the image to be recorded in the first region and second input data of the image to be recorded in the second region to reduce a difference between a density of the image recorded in the first region using the first nozzle group with respect to an input of a predetermined color signal and a density of the image recorded in the second region using the second nozzle group with respect to the input of the predetermined color signal, and performing generation processing for generating dot data indicating a position of a dot to be generated in each of the first region and the second region based on the dot data after the conversion processing;
and
acquiring edge information indicating a pixel corresponding to a first edge of an object in the image to be recorded in the first region and indicating a pixel corresponding to a second edge of the object in the image to be recorded in the second region,
wherein, based on the acquired edge information, processing includes performing the conversion processing and performing the generation processing in such a manner that a color signal of an edge pixel corresponding to an edge is increased/reduced to a degree lower than a degree to which a color signal of a non-edge pixel corresponding to a non-edge of the object is increased/reduced.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 16/929,792Filed 15 Jul 2020
Priority: JP JP2019-14156231 Jul 2019
Published: US 2021/0031538 A14 Feb 2021
Granted: 15 Feb 2022
Term ends: Not estimatedThe source records don’t support an estimate.

Classification28 codes

B41J 2/2139
Print quality control characterised by dot disposition, e.g. for reducing white stripes or banding: compensation for malfunctioning nozzles…
B41J 2/2056
For printing a discrete number of tones: by ink density change
B41J 2/2146
Print quality control characterised by dot disposition, e.g. for reducing white stripes or banding: for line print heads
G06K 15/102
By matrix printers: using ink jet print heads