Image processing apparatus, image forming apparatus, image processing system, and image processing method
First Claim
1. An image processing apparatus, comprising:
- a feature point detection section for detecting feature points included in input image data; and
a features calculation section for calculating features of the input image data in accordance with relative positions of the feature points detected by the feature point detection section,the feature point detection section including;
a partial image extraction section for extracting, from the input image data, a partial image made of a plurality of pixels including a target pixel, an index for indicating busyness of the partial image being not less than a predetermined threshold value;
a rotated image generating section for generating a self-rotated image by rotating the partial image which has been extracted by the partial image extraction section by a predetermined angle;
a matching test determination section for determining whether an image pattern included in the partial image matches an image pattern included in the self-rotated image or not, when the partial image is caused to overlap the self-rotated image; and
a detection section for detecting, as each of the feature points, (a) a target pixel in the partial image including the image pattern determined by the matching test determination section as matching the image pattern included in the self-rotated image, or (b) a block made of a plurality of pixels including the target pixel.
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Accused Products
Abstract
There are provided: a pattern detection process section for extracting a partial image made of pixels including a target pixel from input image data; a rotated image generating section for generating a self-rotated image by rotating the partial image; and a matching test determination section for determining whether an image pattern included in the partial image matches an image pattern included in the self-rotated image. When it is determined that matching exists, a target pixel in the partial image or a block made of pixels including the target pixel is regarded as a feature point. Consequently, even when image data has been read while skewed with respect to a predetermined positioning angle of a reading position of an image reading apparatus or image data has been subjected to enlarging, reducing etc., a feature point properly specifying the image data can be extracted regardless of skew, enlarging, reducing etc.
10 Citations
13 Claims
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1. An image processing apparatus, comprising:
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a feature point detection section for detecting feature points included in input image data; and a features calculation section for calculating features of the input image data in accordance with relative positions of the feature points detected by the feature point detection section, the feature point detection section including; a partial image extraction section for extracting, from the input image data, a partial image made of a plurality of pixels including a target pixel, an index for indicating busyness of the partial image being not less than a predetermined threshold value; a rotated image generating section for generating a self-rotated image by rotating the partial image which has been extracted by the partial image extraction section by a predetermined angle; a matching test determination section for determining whether an image pattern included in the partial image matches an image pattern included in the self-rotated image or not, when the partial image is caused to overlap the self-rotated image; and a detection section for detecting, as each of the feature points, (a) a target pixel in the partial image including the image pattern determined by the matching test determination section as matching the image pattern included in the self-rotated image, or (b) a block made of a plurality of pixels including the target pixel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An image processing system, comprising an image processing apparatus and a server communicably connected with the image processing apparatus,
one of the image processing apparatus and the server including a feature point detection section for detecting feature points included in input image data and a features calculation section for calculating features of the input image data in accordance with relative positions of the feature points detected by the feature point detection section, or the feature point detection section and the features calculation section being divided into the image processing apparatus and the server, the feature point detection section including: -
a partial image extraction section for extracting, from the input image data, a partial image made of a plurality of pixels including a target pixel, an index for indicating busyness of the partial image being not less than a predetermined threshold value; a displaced image generating section for generating a self-rotated image by displacing at least a part of the partial image, which has been extracted by the partial image extraction section, with an other part of the partial image; a matching test determination section for determining whether an image pattern included in the partial image matches an image pattern included in the self-rotated image or not, when the partial image is caused to overlap the self-rotated image; and a detection section for detecting, as each of the feature points, (a) a target pixel in the partial image including the image pattern determined by the matching test determination section as matching the image pattern included in the self-rotated image, or (b) a block made of a plurality of pixels including the target pixel.
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12. An image processing method, comprising the steps of:
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(I) detecting feature points included in input image data; and (II) calculating features of the input image data in accordance with relative positions of the feature points detected in the step (I), the step (I) including the substeps of; (i) extracting, from the input image data, a partial image made of a plurality of pixels including a target pixel, an index for indicating busyness of the partial image being not less than a predetermined threshold value; (ii) generating a self-rotated image by displacing at least a part of the partial image, which has been extracted, with an other part of the partial image; (iii) determining whether an image pattern included in the partial image matches an image pattern included in the self-rotated image or not, when the partial image is caused to overlap the self-rotated image; and (iv) detecting, as each of the feature points, (a) a target pixel in the partial image including the image pattern determined in the substep (iii) as matching the image pattern included in the self-rotated image, or (b) a block made of a plurality of pixels including the target pixel.
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13. A non-transitory computer-readable storage medium in which a program for causing an image processing apparatus to operate is stored,
the image processing apparatus including: -
a feature point detection section for detecting feature points included in input image data; and a features calculation section for calculating features of the input image data in accordance with relative positions of the feature points detected by the feature point detection section, the feature point detection section including; a partial image extraction section for extracting, from the input image data, a partial image made of a plurality of pixels including a target pixel, an index for indicating busyness of the partial image being not less than a predetermined threshold value; a displaced image generating section for generating a self-rotated image by displacing at least a part of the partial image, which has been extracted by the partial image extraction section, with an other part of the partial image; a matching test determination section for determining whether an image pattern included in the partial image matches an image pattern included in the self-rotated image or not, when the partial image is caused to overlap the self-rotated image; and a detection section for detecting, as each of the feature points, (a) a target pixel in the partial image including the image pattern determined by the matching test determination section as matching the image pattern included in the self-rotated image, or (b) a block made of a plurality of pixels including the target pixel, the program causing a computer to function as the feature point detection section.
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Specification