US5025478A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting false edges in an image
Assignee: IPG Electronics 503 Ltd
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Filing: 1990-03-19
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Granted: 1991-06-18
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Expires: 2010-03-19
Abstract
Abstract A method of and apparatus for processing a picture signal for transmission in which the picture signal (Y) is applied to a segmentation device (2) where it is subjected to a segmentation algorithm to identify regions of similar intensity. The resulting region signal is applied to a modal filter (9) in which region edges are straightened and then to an adaptive contour smoothing circuit (10) in which contour sections identified as representing false edges are filtered. The filtered signal is subtracted from the original luminance signal in a subtractor (12) to produce a luminance texture signal which is encoded by a texture encoder (17). The region signal is encoded in a region encoder (24) together with flags indicating which of the contours in the region signal represent false edges.
Inventors
- 👤 Octavius J. Morris
- 👤 David Moran
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:26
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/409; H04N19/00; G; G06; G06T; G06T5/00; G06T5/20; G06T5/70; G06T7/00; G06T7/10; G06T7/12; H04N19/80; G06T2207/00; G06T2207/10; G06T2207/10016; G06T2207/20; G06T2207/20004; G06T2207/20012; G06T2207/20172; G06T2207/20192; H04N19/20; H04N19/30
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
207 words
A method of processing a picture signal for conveyance by means of a transmission path or storage medium, said method comprising the steps of: i) producing a picture signal which corresponds to a picture, ii) subjecting said picture signal to a segmentation algorithm to produce a region signal which identifies edges and closed regions in said picture, iii) producing a texture signal which corresponds to the difference between said picture signal and said region signal, characterised in that said method comprises the further steps of iv) selecting, at least a portion of a boundary between two adjacent regions in said region signal, v) determining the mean values of the region signal in areas immediately adjacent to and on either side of said boundary portion and forming the difference between these mean values, vi) determining the mean values of the picture signal in corresponding areas immediately adjacent to and on either side of the boundary portion identified in said region signal and forming the difference between these means values, vii) comparing the said difference obtained in step (v) with that obtained in step (vi), and viii) using the result of the comparison performed in step (vii) to determine whether the said boundary represents a true or false edge.
Claim 2
Independent Claim
207 words
A method of processing a picture signal for conveyance by means of a transmission path or storage medium, said method comprising the steps of: i) producing a picture signal which corresponds to a picture, ii) subjecting said picture signal to a segmentation algorithm to produce a region signal which identifies edges and closed regions in said picture, iii) producing a texture signal which corresponds to the difference between said picture signal and said region signal, characterised in that said method comprises the further steps of iv) selecting, at least a portion of a boundary between two adjacent regions in said region signal, v) determining the mean values of the region signal in areas immediately adjacent to and on either side of said boundary portion and forming the difference between these mean values, vi) determining the mean values of the picture signal in corresponding areas immediately adjacent to and on either side of the boundary portion identified in said region signal and forming the difference between these means values, vii) comparing the said difference obtained in step (v) with that obtained in step (vi), and viii) using the result of the comparison performed in step (vii) to determine whether the said boundary represents a true or false edge.
Claim 3
Dependent Claim
87 words
A method as claimed in claim 1, characterised in that the said comparison performed in step (vii) is between a scaled version of the difference obtained in step (v) with the difference obtained in step (vi), the scaling factor being chosen so that if the scaled difference obtained in step (v) approximates the difference obtained in step (vi) the said boundary represents a true edge but if the said scaled difference is greater than the difference obtained in step (vi) the said boundary represents a false edge.
Claim 4
Dependent Claim
38 words
A method as claimed in claim 1, characterised in that the magnitude of the difference derived in step (v) is determined and the comparison of step (vii) is only performed if this magnitude is below a given value.
Claim 5
Dependent Claim
208 words
Apparatus for processing a picture signal for conveyance by means of a transmission path or storage medium, said apparatus comprising means for producing a picture signal which corresponds to a picture, means for subjecting said picture signal to a segmentation algorithm to produce a region signal which identifies edges and closed regions in said picture, means for producing a texture signal which corresponds to the difference between said picture signal and said region signal, characterised in that said apparatus further comprises further means for selecting at least a portion of a boundary between two adjacent regions in said region signal, means for determining the mean values of the region signal in areas immediately adjacent to and on either side of said boundary portion and forming the difference between these mean values, means for determining the mean values of the picture signal in corresponding areas immediately adjacent to and on either side of the boundary portion identified in said region signal and forming the difference between these mean values, means for comparing the said difference obtained in said region signal with that obtained in said picture signal, and means for using the result of the said comparison to determine whether the said boundary represents a true or false edge.
Claim 6
Dependent Claim
208 words
Apparatus for processing a picture signal for conveyance by means of a transmission path or storage medium, said apparatus comprising means for producing a picture signal which corresponds to a picture, means for subjecting said picture signal to a segmentation algorithm to produce a region signal which identifies edges and closed regions in said picture, means for producing a texture signal which corresponds to the difference between said picture signal and said region signal, characterised in that said apparatus further comprises further means for selecting at least a portion of a boundary between two adjacent regions in said region signal, means for determining the mean values of the region signal in areas immediately adjacent to and on either side of said boundary portion and forming the difference between these mean values, means for determining the mean values of the picture signal in corresponding areas immediately adjacent to and on either side of the boundary portion identified in said region signal and forming the difference between these mean values, means for comparing the said difference obtained in said region signal with that obtained in said picture signal, and means for using the result of the said comparison to determine whether the said boundary represents a true or false edge.
Claim 7
Dependent Claim
76 words
Apparatus as claimed in claim 4, characterised in that it further comprises means for obtaining a scaled version of the difference obtained in said region signal, the scaling factor being chosen so that if the scaled difference obtained approximates the difference obtained in the picture signal the said boundary represents a true edge but if the said scaled difference is greater than the difference obtained in the picture signal the said boundary represents a false edge.
Claim 8
Dependent Claim
45 words
Apparatus as claimed in claim 4, characterised in that said apparatus further comprises means for determining the magnitude of the difference in said region signal and for preventing the comparing of the said differences being performed if the said magnitude is above a given value.
Claim 9
Dependent Claim
38 words
A method as claimed in claim 2, characterized in that the magnitude of the difference derived in step (v) is determined and the comparison of step (vii) is only performed if this magnitude is below a given value.
Claim 10
Dependent Claim
45 words
Apparatus as claimed in claim 5, characterized in that said apparatus further comprises means for determining the magnitude of the difference in said region signal and for preventing the comparing of the said differences being performed in the said magnitude is above a given value.
References Cited (Backward Citations)
US4553165A
Cited
US4644583A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-06-17 | 1994-12-17 | 1995-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-17 | 1998-12-17 | 1999-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-17 | 2002-12-17 | 2003-06-18 | $7700.00 | Window Closed / Lapsed |