EP0451579A2
Expired / Lapsed
EP
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Apparatus for reading images and method for enhancing the outlines of shapes
Assignee: Dainippon Screen Manufacturing Co Ltd
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Filing: 1991-03-22
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Granted: —
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Expires: 2011-03-22
Abstract
Abstract The present invention relates to a method for enhancing the outline of shapes that occur in an original image which has been obtained by the use of an electro-optical scanner or similar device for the purposes of preparation for printing. The apparatus for reading images comprises the RAM 12 where plural sets of data having the relationships between the difference signal S-U and the enhancement signal K.(S-U) are stored. By selecting a proper set, the outline enhancement or graininess sublimation threshold setting can be set according color values and other photo aspects of the original, or according to the design of the original image and it's intended use.
Inventors
- 👤 Takashi Dainippon Screen Mfg. Co. Ltd. Sakamoto
- 👤 Makoto Dainippon Screen Mfg. Co. Ltd. Hirosawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 10:52
CPC Classifications
G; G06; G06T; G06T5/00; G06T5/73; G06T5/75; G06T5/20; H; H04; H04N; H04N1/00; H04N1/40; H04N1/409; H04N1/4092
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
158 words
An apparatus for reading images, that has the function of enhancing the outlines within those images, comprises: (a) means for producing a sharp signal which is an image signal derived from scanning an attention point in the original image; (b) means for producing an unsharp signal derived by averaging the values of image signals obtained by scanning predetermined pixels adjacent to the attention point; (c) means for producing an enhancement value that is calculated by multiplying an enhancement coefficient times a differential signal which has itself been calculated by subtracting the unsharp signal from the sharp signal; the enhancement coefficient shall be set effectively to 0 when the absolute value of the differential signal is less than a predetermined threshold value; the predetermined threshold value shall vary according to the value of the sharp signal or the unsharp signal; and (d) means for producing an enhanced image signal derived from adding the enhancement value to the sharp signal.
Claim 2
Dependent Claim
17 words
An apparatus in accordance with claim 1 wherein: said sharp signal is produced as an analog signal.
Claim 3
Dependent Claim
17 words
An apparatus in accordance with claim 1 wherein: said sharp signal is produced as a digital signal.
Claim 4
Dependent Claim
21 words
An apparatus in accordance with claim 3 wherein: said predetermined threshold value is determined by a table stored in a memory.
Claim 5
Dependent Claim
16 words
An apparatus in accordance with claim 3 wherein: said predetermined threshold value is determined by computing.
Claim 6
Independent Claim
162 words
A method for reading images, that has the function of enhancing the outlines within those images, comprises: (a) a step of producing a sharp signal which is an image signal derived from scanning an attention point in the original image; (b) a step of producing an unsharp signal derived by averaging the values of image signals obtained by scanning predetermined pixels adjacent to the attention point; (c) a step of producing an enhancement value that is calculated by multiplying an enhancement coefficient times a differential signal which has itself been calculated by subtracting the unsharp signal from the sharp signal; the enhancement coefficient shall be set effectively to 0 when the absolute value of the differential signal is less than a predetermined threshold value; the predetermined threshold value shall vary according to the value of the sharp signal or the unsharp signal; and (d) a step of producing an enhanced image signal derived from adding the enhancement value to the sharp signal.
Claim 7
Dependent Claim
17 words
A method in accordance with claim 6 wherein: said sharp signal is produced as an analog signal.
Claim 8
Dependent Claim
17 words
A method in accordance with claim 6 wherein: said sharp signal is produced as a digital signal.
Claim 9
Dependent Claim
21 words
A method in accordance with claim 8 wherein: said predetermined threshold value is determined by a table stored in a memory.
Claim 10
Dependent Claim
16 words
A method in accordance with claim 8 wherein: said predetermined threshold value is determined by computing.
References Cited (Backward Citations)
No citation records indexed.
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