US4996603A
Expired / Lapsed
US
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Image processing system
Assignee: PFU Ltd
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Filing: 1989-06-28
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Granted: 1991-02-26
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Expires: 2009-06-28
Abstract
Abstract An image processing system for obtaining a binary signal from a multi-level signal read by an image scanner from an original document including mixed characters, ruled lines, and photos, and then obtaining a reproduced image from the binary signal, the image processing system including: a fixed slice processing unit for receiving said multi-level signal, and for slicing the multi-level signal by a predetermined fixed threshold level, and outputting the binary signal sliced by the fixed threshold level; a half-tone processing unit for receiving the multi-level signal, and for slicing the multi-level signal by a plurality of threshold levels defined by a dither method, and outputting the binary signal sliced by the plural threshold levels defined by the dither method; a character/photo separating unit for receiving the multi-level signal; and for detecting a pattern of the multi-level signal, separating either a character portion or photo portion based on the pattern, and outputting a selection signal; a selection unit for selecting either the fixed slice processing unit or the half-tone processing unit based on the selection signal from the character/photo separating unit.
Inventors
- 👤 Norio Kanemitsu
- 👤 Yoshio Tabata
- 👤 Masaru Wakabayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:54
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40062
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
256 words
An image processing system for obtaining a binary signal from a multi-level signal read by an image scanner from an original document including mixed characters, ruled lines, and photos, and then obtaining a reproduced image from said binary signal, said image processing system comprising; fixed slice processing means for receiving said multi-level signal, for slicing said multi-level signal by a predetermined fixed threshold level, and for outputting said binary signal sliced by said fixed threshold level; half-tone processing means for receiving said multi-level signal, for slicing said multi-level signal by a plurality of threshold levels defined by a dither method, and for outputting said binary signal sliced by said plurality of threshold levels defined by said dither method; character/photo separating means for receiving said multi-level signal, for detecting a pattern of said multi-level signal, for separating either a character portion or a photo portion based on said pattern and for outputting a selection signal, said character/photo separating means comprises a successive gray color detection circuit for receiving said multi-level signal, and for obtaining binary signals after slicing said multi-level signal based on said fixed threshold level, and detecting a number of said binary signals occurring in succession within one line of said binary signal; and a fine line detection circuit for receiving said multi-level signal, and for detecting a change of density level of said multi-levels signal between adjacent lines; and selection means for selecting either said fixed slice processing means or said half-tone processing means based on said selection signal from said character/photo separating means.
Claim 2
Dependent Claim
256 words
An image processing system for obtaining a binary signal from a multi-level signal read by an image scanner from an original document including mixed characters, ruled lines, and photos, and then obtaining a reproduced image from said binary signal, said image processing system comprising; fixed slice processing means for receiving said multi-level signal, for slicing said multi-level signal by a predetermined fixed threshold level, and for outputting said binary signal sliced by said fixed threshold level; half-tone processing means for receiving said multi-level signal, for slicing said multi-level signal by a plurality of threshold levels defined by a dither method, and for outputting said binary signal sliced by said plurality of threshold levels defined by said dither method; character/photo separating means for receiving said multi-level signal, for detecting a pattern of said multi-level signal, for separating either a character portion or a photo portion based on said pattern and for outputting a selection signal, said character/photo separating means comprises a successive gray color detection circuit for receiving said multi-level signal, and for obtaining binary signals after slicing said multi-level signal based on said fixed threshold level, and detecting a number of said binary signals occurring in succession within one line of said binary signal; and a fine line detection circuit for receiving said multi-level signal, and for detecting a change of density level of said multi-levels signal between adjacent lines; and selection means for selecting either said fixed slice processing means or said half-tone processing means based on said selection signal from said character/photo separating means.
Claim 3
Dependent Claim
34 words
An image processing system as claimed in claim 1, wherein said successive gray color detection circuit has a plurality of detection circuits each having either said first threshold level or said second threshold level.
Claim 4
Dependent Claim
35 words
An image processing system as claimed in claim 1, wherein said fine line detection circuit comprises a primary differential circuit and a secondary differential circuit, each inputting a multi-level signal from a plurality of lines.
Claim 5
Dependent Claim
44 words
An image processing system as claimed in claim 1, wherein said character/photo separating means further comprises a decision means for determining either a character portion or photo portion based on outputs from said successive gray color detection circuit and said fine line detection circuit.
Claim 6
Dependent Claim
61 words
An image processing system as claimed in claim 1, wherein said fixed threshold level in said successive gray color detection circuit is set to either a first threshold level or a second threshold level, said first threshold level being set in the neighborhood of a white color, and said second threshold level being set in the neighborhood of a black color.
Claim 7
Dependent Claim
34 words
An image processing system as claimed in claim 4, wherein said successive gray color detection circuit has a plurality of detection circuits each having either said first threshold level or said second threshold level.
Claim 8
Dependent Claim
34 words
An image processing system as claimed in claim 5, wherein said successive gray color detection circuit has a plurality of detection circuits each having either said first threshold level or said second threshold level.
References Cited (Backward Citations)
US4707745A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-25 | 1994-08-27 | 1995-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-25 | 1998-08-27 | 1999-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-25 | 2002-08-27 | 2003-02-26 | $7700.00 | Window Closed / Lapsed |