Image processing apparatus, image forming apparatus, image reading process apparatus, image processing method, image processing program, and computer-readable storage medium
First Claim
1. An image processing apparatus comprising:
- halftone frequency determining means for determining a halftone frequency of an inputted image, the halftone frequency determining means comprising;
flat halftone discriminating means for extracting information of density distribution per segment block consisting of a plurality of pixels, and discriminating, based on the information of density distribution, whether the segment block is a flat halftone region in which density transition is low or of a non-flat halftone region in which the density transition is high;
extracting means for extracting a feature of density transition between pixels of the segment block which the flat halftone discriminating means discriminates as the flat halftone region; and
halftone frequency estimating means for estimating the halftone frequency, based on the feature extracted by the extracting means.
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Accused Products
Abstract
The halftone frequency determining section is provided with a flat halftone discriminating section for extracting information of density distribution per segment block, and discriminating, based on the information of density distribution, whether the segment block is a flat halftone region in which density transition is low or of a non-flat halftone region in which the density transition is high; a threshold value setting section for setting a threshold value for use in binarization; a binarization section for performing the binarization in order to generate binary data of each pixel in the segment block according to the threshold value; a transition number calculating section for calculating out transition numbers of the binary data; and a maximum transition number averaging section for averaging the transition numbers which are of the segment block discriminated as the flat halftone region by the flat halftone discriminating section, and which are calculated out by a maximum transition number calculating section. A halftone frequency is determined (i.e., found out) based on only the maximum transition number average of the segment block discriminated as the flat halftone region. With this, it is possible to provide an image processing apparatus that can determine the halftone frequency highly accurately.
16 Citations
18 Claims
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1. An image processing apparatus comprising:
halftone frequency determining means for determining a halftone frequency of an inputted image, the halftone frequency determining means comprising;
flat halftone discriminating means for extracting information of density distribution per segment block consisting of a plurality of pixels, and discriminating, based on the information of density distribution, whether the segment block is a flat halftone region in which density transition is low or of a non-flat halftone region in which the density transition is high;
extracting means for extracting a feature of density transition between pixels of the segment block which the flat halftone discriminating means discriminates as the flat halftone region; and
halftone frequency estimating means for estimating the halftone frequency, based on the feature extracted by the extracting means. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An image forming apparatus comprising:
an image processing apparatus comprising;
halftone frequency determining means for determining a halftone frequency of an inputted image, the halftone frequency determining means comprising;
flat halftone discriminating means for extracting information of density distribution per segment block consisting of a plurality of pixels, and discriminating, based on the information of density distribution, whether the segment block is a flat halftone region in which density transition is low or of a non-flat halftone region in which the density transition is high;
extracting means for extracting a feature of density transition between pixels of the segment block which the flat halftone discriminating means discriminates as the flat halftone region; and
halftone frequency estimating means for estimating the halftone frequency, based on the feature extracted by the extracting means.
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9. An image reading process apparatus comprising:
an image processing apparatus comprising;
halftone frequency determining means for determining a halftone frequency of an inputted image, the halftone frequency determining means comprising;
flat halftone discriminating means for extracting information of density distribution per segment block consisting of a plurality of pixels, and discriminating, based on the information of density distribution, whether the segment block is a flat halftone region in which density transition is low or of a non-flat halftone region in which the density transition is high; and
extracting means for extracting a feature of density transition between pixels of the segment block which the flat halftone discriminating means discriminates as the flat halftone region; and
halftone frequency estimating means for estimating the halftone frequency, based on the feature extracted by the extracting means.
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10. An image processing method comprising:
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determining a halftone frequency of an inputted image, the step of determining the halftone frequency comprising;
discriminating a flat halftone, the step of discriminating including (a) extracting information of density distribution per segment block consisting of a plurality of pixels, and (b) discriminating, based on the information of density distribution, whether the segment block is a flat halftone region in which density transition is low or of a non-flat halftone region in which the density transition is high; and
extracting a feature of density transition between pixels of the segment block which is discriminated as the flat halftone region; and
estimating the halftone frequency, based on the feature extracted. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. An image processing program for operating an image processing apparatus comprising halftone frequency determining means for determining a halftone frequency of an inputted image,
the halftone frequency determining means comprising: -
flat halftone discriminating means for extracting information of density distribution per segment block consisting of a plurality of pixels, and discriminating, based on the information of density distribution, whether the segment block is a flat halftone region in which density transition is low or of a non-flat halftone region in which the density transition is high;
extracting means for extracting a feature of density transition between pixels of the segment block which the flat halftone discriminating means discriminates as the flat halftone region; and
halftone frequency estimating means for estimating the halftone frequency, based on the feature extracted by the extracting means, and the program causing a computer to serve as each means.
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18. A computer-readable recording medium in which an image processing program for operating an image processing apparatus comprising halftone frequency determining means for determining a halftone frequency of an inputted image is stored,
the halftone frequency determining means comprising: -
flat halftone discriminating means for extracting information of density distribution per segment block consisting of a plurality of pixels, and discriminating, based on the information of density distribution, whether the segment block is a flat halftone region in which density transition is low or of a non-flat halftone region in which the density transition is high;
extracting means for extracting a feature of density transition between pixels of the segment block which the flat halftone discriminating means discriminates as the flat halftone region; and
halftone frequency estimating means for estimating the halftone frequency, based on the feature extracted by the extracting means, and the program causing a computer to serve as each means.
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Specification