Image processing apparatus, image processing method, and storage medium
AssigneeCanon Kabushiki Kaisha
InventorRyosuke Otani
Life of this patent
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Abstract
An image processing apparatus according to an embodiment of the present invention includes: a first generation unit that generates a low-frequency image by extracting a low-frequency component from an input image; a second generation unit that generates a high-frequency image by extracting a high-frequency component from the input image; a screen processing unit that generates an AM screen image by performing AM screen processing on the low-frequency image; an addition processing unit that generates an added image by adding the high-frequency image to the AM screen image; and a correction unit that corrects the added image.
Claims20
An image processing apparatus comprising:
- one or more processors;
- and
- one or more memories that store instructions executable by the one or more processors to cause the image processing apparatus to act as plurality of units comprising:
- (1) a first generation unit that generates a low-frequency image by extracting a low-frequency component from an input image;
- (2) a second generation unit that generates a high-frequency image by extracting a high-frequency component from the input image;
- (3) a screen processing unit that generates an AM screen image by performing AM screen processing on the low-frequency image;
- (4) an addition processing unit that generates an added image by adding the high-frequency image to the AM screen image;
- and
- (5) a correction unit that corrects the added image,
- wherein the added image is an image in which a pixel value out of a specified gradation range was replaced with a pixel value within the specified gradation range as a result of adding the high-frequency image to the AM screen image, and
- wherein the correction unit distributes a difference between the pixel value before the replacement and the pixel value after the replacement occurred in the pixel the pixel value of which was replaced with the pixel value within the specified gradation range, to pixels other than the pixels the pixel value of which was replaced with the pixel value within the specified gradation range.
An image processing method performed by an image processing apparatus including one or more processors and one or more memories that store instructions executable by the one or more processors, the method comprising the steps of:
- generating a low-frequency image by extracting a low-frequency component from an input image;
- generating a high-frequency image by extracting a high-frequency component from the input image;
- generating an AM screen image by performing AM screen processing on the low-frequency image;
- generating an added image by adding the high-frequency image to the AM screen image;
- and
- correcting the added image, wherein
- the added image is an image in which a pixel value of pixels out of a specified gradation range was replaced with a pixel value within the specified gradation range as a result of adding the high-frequency image to the AM screen image, and
- wherein the correcting the added image includes distributing a difference between the pixel value before the replacement and the pixel value after the replacement occurred in the pixel the pixel value of which was replaced with the pixel value within the specified gradation range, to pixels other than the pixels the pixel value of which was replaced with the pixel value within the specified gradation range.
A non-transitory computer-readable storage medium storing a program for causing a computer to perform an image processing method, the method comprising the steps of:
- generating a low-frequency image by extracting a low-frequency component from an input image;
- generating a high-frequency image by extracting a high-frequency component from the input image;
- generating an AM screen image by performing AM screen processing on the low-frequency image;
- generating an added image by adding the high-frequency image to the AM screen image;
- and
- correcting the added image, wherein
- the added image is an image in which a pixel value out of a specified gradation range was replaced with a pixel value within the specified gradation range as a result of adding the high-frequency image to the AM screen image, and
- wherein the correcting the added image includes distributing a difference between the pixel value before the replacement and the pixel value after the replacement occurred in the pixel the pixel value of which was replaced with the pixel value within the specified gradation range, to pixels other than the pixels the pixel value of which was replaced with the pixel value within the specified gradation range.
Dependencies are inferred from the claim text.