Image analysis – Image enhancement or restoration – Edge or contour enhancement
Reexamination Certificate
1998-10-27
2001-09-04
Lee, Thomas D (Department: 2624)
Image analysis
Image enhancement or restoration
Edge or contour enhancement
C382S199000
Reexamination Certificate
active
06285800
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an apparatus and a method for processing an image which allows an improvement in the resolution of an edge portion and fine lines of the image while enabling the reproducibility of gradation of a non-edge portion of the image to be maintained.
2. Description of Related Art
Various techniques for enabling the image of an original document read out by such an image reading device as the scanner to be reproduced as faithfully as permissible in the form of a printed image have been heretofore proposed.
One of these techniques which is disclosed in JP-A-09-191,402, for example, comprises preparing two matrixes different in resolving power and identical in size and selecting either of the matrixes which conforms the characteristic to be required of a relevant image thereby effecting the maintenance of the resolving power in a region in need of the resolving power and attaining the reproducibility of gradation in a region in need of reproducibility of gradation.
When such an area gradation reproduction method as mentioned above is adopted, however, an effort to obtain the reproducibility of gradation in a wide range generally results in inevitably creating discontinuous contours between an edge portion and fine lines of the image resulting in a rugged sensation and degrading the resolution thereof. Conversely, when important consideration is given to the resolution, the problem of having to sacrifice the reproducibility of gradation arises in spite of the advantage that the edge portion and fine lines are reproduced with clearly defined contours.
SUMMARY OF THE INVENTION
This invention, initiated as motivated in light of such disadvantages of the conventional apparatus and method for processing an image as mentioned above, has for a main object thereof the provisions of an apparatus and a method for processing an image which are capable of performing on the image the processing optimum for the characteristic of the image.
Another object of this invention is to provide an apparatus and a method for processing an image which are capable of performing on the image the processing in conformity with the characteristic of the image without impairing the gradation and the resolution.
A further object of this invention is to provide an apparatus and a method for processing an image which are capable of realizing the processing optimum for the characteristic of the image with a simple construction.
According to one aspect of the invention, an image processing apparatus is provided for converting M gradation image data into N gradation image data, wherein N is less than M, comprising determining means, based on the M gradation image data of a target region, for determining whether the target region corresponds to an edge portion or to a non-edge portion and processing means, based on the determination by said determining means, for generating the N gradation image data of the target region by using a first matrix in a case where the target region corresponds to the edge portion and for generating the N gradation image data of the target region by using a part of a second matrix in a case where the target region corresponds to the non-edge portion.
According to another aspect of the invention, an image processing method is provided for converting M gradation image data into N gradation image data, wherein N is less than M, comprising the steps of (a) determining, based on the M gradation image data of a target region, whether the target region corresponds to an edge portion or to a non-edge portion, and selectively, (b-
1
) generating the N gradation image data of the target region by using a first matrix in a case where the target region corresponds to the edge portion in accordance with the determination in the step (a), and (b-
2
) selecting one of a plurality of parts of a second matrix and generating the N gradation image data of the target region by using the selected part of the second matrix in a case where the target region corresponds to the non-edge portion in accordance with the determination in the step (a).
According to still another aspect of the invention, storage is provided for storing a computer readable program with which a computer executes a process including the steps of (a) determining, based on M gradation image data of a target region, whether the target region corresponds to an edge portion or to a non-edge portion, and selectively, (b-1) generating N gradation image data of the target region by using a first matrix in a case where the target region corresponds to the edge portion in accordance with the determination in the step (a), and (b-2) selecting one of a plurality of parts of a second matrix and generating the N gradation image data of the target region by using the selected part of the second matrix in a case where the target region corresponds to the non-edge portion in accordance with the determination in the step (a), wherein N is less than M.
According to a further aspect of the invention, an image processing apparatus is provided for converting M gradation image data into N gradation image data, wherein N is less than M, comprising determining means for determining an attribute of the M gradation image data of a target region and for generating a composite data of the target region from the M gradation image data and the attribute of the target region and processing means, based on the composite data of the target region, for generating the N gradation image data of the target region by using one of a plurality of matrixes, wherein the processing means selects the one of the plurality of matrixes based on the attribute included in the composite data of the target region.
According to a still further aspect of the invention, an image processing method is provided for converting M gradation image data into N gradation image data, wherein N is less than M, comprising the steps of (a) determining an attribute of the M gradation image data of a target region, (b) generating a composite data of the target region from the M gradation image data and the attribute of the target region, (c) selecting one of a plurality of matrixes based on the attribute included in the composite data of the target region and (d) generating, based on the composite data of the target region, the N gradation image data of the target region by using the matrix selected in the step (c).
REFERENCES:
patent: 5243445 (1993-09-01), Koike
patent: 5978554 (1999-11-01), Hakamada et al.
patent: 0562162 A1 (1993-09-01), None
patent: 63-169174 (1988-07-01), None
patent: 10-191054 (1993-09-01), None
patent: 8-307690 (1996-11-01), None
patent: 9-191402 (1997-07-01), None
Katori Kentaro
Takemoto Shinichi
Toyoshi Naoki
Yamazaki Tsutomu
Brinich Stephen
Lee Thomas D
Minolta Co. , Ltd.
Sidley Austin Brown & Wood
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