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EP0899685B1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Image processing apparatus for discriminating image field of original document plural times and method therefor

Assignee: Toshiba Corp
•
Filing: 1998-08-19
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Granted: 2002-10-23
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Expires: 2018-08-19
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Abstract

No abstract record available.

Inventors

  • 👤 Naofumi Yamamoto
  • 👤 Haruko Kawakami
  • 👤 Gururaj Rao

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 10:37
CPC Classifications
G; G06; G06T; G06T7/00; G06T7/10; G06T7/11; G06V; G06V30/00; G06V30/10; G06V30/16; G06V30/162; G06V30/18; G06V30/18105; G06V30/40; G06V30/41; G06V30/414; G06T2207/00; G06T2207/10; G06T2207/10004; G06T2207/10008; G06T2207/30; G06T2207/30176

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 148 words
An image processing apparatus, comprising field separating means (1201) for separating an original image into fields of a plurality of different types in response to a first image signal obtained at a first resolution of the original image, characteristic value calculating means (1202, 1311) for calculating a characteristic value of the original image in response to a second image signal of the original image obtained at a second resolution which is higher than the first resolution, discrimination means (1312, 1313) for discriminating an image field of the original image in accordance with the characteristic value calculated by the characteristic value calculating means and the type of the image field as separated by the field separating means, and an image processing means (1004) for performing a predetermined image processing corresponding to the result of discrimination of the image field performed by the discrimination means, on the second image signal.
Claim 2
Dependent Claim 46 words
An image processing apparatus according to claim 1, characterized in that each of the field separation means and the characteristic value calculating means further includes scanning means (1001) for scanning the original image at the first resolution and then scanning the same at the second resolution.
Claim 3
Dependent Claim 45 words
An image processing apparatus according to claim 1 or 2, characterized in that the field separating means includes means (1201) for separating the original image into at least a usual character field, characters on a background, a continuous gradation field and a dot gradation field.
Claim 4
Dependent Claim 52 words
An image processing apparatus according to one of claims 1 to 3, characterized by means for deleting a gradation image existing in a field which has not been discriminated by the field separating means as a gradation field and a gradation image existing in a field discriminated as a continuous gradation field.
Claim 5
Dependent Claim 68 words
An image processing apparatus according to one of claims 1 to 4, characterized in that the characteristic value calculating means (1202, 1311) includes means (1311a-c) for calculating a change in the density, an average density and chroma which are characteristic values of the original image in response to the second image signal of the original image obtained at the second resolution which is higher than the first resolution.
Claim 6
Dependent Claim 73 words
An image processing apparatus according to one of claims 1 to 5, characterized in that the characteristic value calculating means (1202, 1311) includes means for calculating a characteristic value of the original image in each of unit regions having different lengths in a main scanning direction and a sub-scanning direction in response to the second image signal of the original image obtained at the second resolution which is higher than the first resolution.
Claim 7
Dependent Claim 63 words
An image processing apparatus according to one of claims 1 to 6, characterized in that the discrimination means includes second discrimination means (1312, 1313) for discriminating the image field of the original image by means of comparing the characteristic value calculated by the characteristic value calculating means with a threshold value corresponding to the type of the field separated by the separating means.
Claim 8
Dependent Claim 74 words
An image processing apparatus according to one of claims 1 to 4, characterized in that the characteristic value calculating means includes a second characteristic value calculating means (2201, 2202) for calculating a segment component of the original image in a main scanning direction and a sub-scanning direction as the characteristic value in response to the second image signal of the original image obtained at the second resolution which is higher than the first resolution.
Claim 9
Dependent Claim 150 words
An image processing method comprising: a field separating step (S1, S2, S3) for separating an original image into fields of a plurality of different types in response to a first image signal obtained at a first resolution of the original image; a characteristic value calculating step (S9) for calculating a characteristic value of the original image in response to a second image signal of the original image obtained at a second resolution which is higher than the first resolution; a discrimination step (S10) for discriminating an image field of the original image in accordance with the characteristic value calculated in the characteristic value calculating step and the type of the image field as separated in the field separating step; and an image processing step for performing a predetermined image processing corresponding to the result of discrimination of the image field performed by the discrimination step, on the second image signal.
Claim 10
Dependent Claim 47 words
An image processing method according to claim 9, characterized in that each of the field separation step and characteristic value calculating step further includes a scanning step (S1, S7) for scanning the original image at the first resolution and then scanning the same at the second resolution.
Claim 11
Dependent Claim 48 words
An image processing method according to claim 9 or 10, characterized in that the field separating step includes a step (S1, S2, S3) for separating the original image into at least a usual character field, characters on a background, a continuous gradation field and a dot gradation field.
Claim 12
Dependent Claim 56 words
An image processing method according to one of claims 9 to 11, characterized by a step (S401 to S409) of deleting a gradation image existing in a field which has not been discriminated in the field separating step as a gradation field and a gradation image existing in a field discriminated as a continuous gradation field.
Claim 13
Dependent Claim 68 words
An image processing method according to one of claims 9 to 12, characterized in that the characteristic value calculating steps includes a step (S9) for calculating a change in a density , an average density and chroma which are characteristic values of the original image in response to the second image signal of the original image obtained at the second resolution which is higher than the first resolution.
Claim 14
Dependent Claim 73 words
An image processing method according to one of claims 9 to 13, characterized in that the characteristic value calculating step includes a step (S9) for calculating a characteristic value of the original image in each of unit regions having different lengths in a main scanning direction and a sub-scanning direction in respond to the second image signal of the original image obtained at the second resolution which is higher than the first resolution.
Claim 15
Dependent Claim 63 words
An image processing method according to one of claims 9 to 14, characterized in that the discrimination step includes a second discrimination step (S10) for discriminating the image field of the original image by means of comparing the characteristic value calculated by the characteristic value calculating step with a threshold value corresponding to the type of the field separated by the separating step.
Claim 16
Dependent Claim 75 words
An image processing method according to one of claims 1 to 12, characterized in that the characteristic value calculating step includes a second characteristic value calculating step (S9) for calculating a segment component of the original image in a main scanning direction and a sub-scanning direction as the characteristic value in response to the second image signal of the original image obtained at the second pixel density which is higher than the first pixel density.

References Cited (Backward Citations)

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