US5719951A
Expired / Lapsed
US
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Normalized image feature processing
Assignee: British Telecommunications PLC
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Filing: 1991-07-17
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Granted: 1998-02-17
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Expires: 2011-07-17
Abstract
Abstract A method of processing an image including the steps of: locating within the image the position of at least one predetermined feature; extracting from the image data representing each feature; and calculating for each feature a feature vector representing the position of the image data of the feature in an N-dimensional space, such space being defined by a plurality of reference vectors each of which is an eigenvector of a training set of like features in which the image data of each feature is modified to normalize the shape of each feature thereby to reduce its deviation from a predetermined standard shape of the feature, which step is carried out before calculating the corresponding feature vector.
Inventors
- 👤 Mark Andrew Shackleton
- 👤 William John Welsh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:23
CPC Classifications
H; H04; H04N; H04N19/00; G; G06; G06V; G06V10/00; G06V10/70; G06V10/74; G06V10/75; G06V10/754; G06V40/00; G06V40/10; G06V40/16; G07; G07C; G07C9/00; G07C9/20; G07C9/22; G07C9/25; H04N19/20
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
147 words
A method of processing an image represented by an array of digital signals, said method comprising the steps off locating within the image array of digital signals the position of at least one predetermined feature; extracting image data from said image array of digital signals representing each said feature; generating for each feature a feature vector digital signal representing the position of the image data of the feature in an N-dimensional space, N being an integer and said space being defined by a plurality of reference vector signals each of which is an eigenvector of a training set of images of like features; and modifying the digital signal image data of each feature to normalize the shape of each feature thereby to reduce its deviation from a predetermined standard shape of said feature, which step is carried out before generating the feature vector signal for each feature.
Claim 2
Independent Claim
147 words
A method of processing an image represented by an array of digital signals, said method comprising the steps off locating within the image array of digital signals the position of at least one predetermined feature; extracting image data from said image array of digital signals representing each said feature; generating for each feature a feature vector digital signal representing the position of the image data of the feature in an N-dimensional space, N being an integer and said space being defined by a plurality of reference vector signals each of which is an eigenvector of a training set of images of like features; and modifying the digital signal image data of each feature to normalize the shape of each feature thereby to reduce its deviation from a predetermined standard shape of said feature, which step is carried out before generating the feature vector signal for each feature.
Claim 3
Independent Claim
164 words
A method of processing an image represented by an array of digital signals, said method comprising the steps of: locating within the image array of digital signals the position of at least one predetermined feature; extracting image data from said image array of digital signals representing each said feature; generating for each feature a feature vector digital signal representing the position of the image data of the feature in an N-dimensional space, N being an integer and said space being defined by a plurality of reference vector signals each of which is an eigenvector of a training set of images of like features; and modifying the digital signal image data of each feature to normalize the shape of each feature thereby to reduce its deviation from a predetermined standard shape of said feature, which step is carried out before generating the feature vector signal for each feature, wherein the step of modifying the digital signal image data of each feature uses a deformable template.
Claim 4
Independent Claim
164 words
A method of processing an image represented by an array of digital signals, said method comprising the steps of: locating within the image array of digital signals the position of at least one predetermined feature; extracting image data from said image array of digital signals representing each said feature; generating for each feature a feature vector digital signal representing the position of the image data of the feature in an N-dimensional space, N being an integer and said space being defined by a plurality of reference vector signals each of which is an eigenvector of a training set of images of like features; and modifying the digital signal image data of each feature to normalize the shape of each feature thereby to reduce its deviation from a predetermined standard shape of said feature, which step is carried out before generating the feature vector signal for each feature, wherein the step of modifying the digital signal image data of each feature uses a deformable template.
Claim 5
Independent Claim
187 words
A method of processing an image represented by an array of digital signals, said method comprising the steps of: locating within the image array of digital signals the position of at least one predetermined feature; extracting image data from said image array of digital signals representing each said feature; generating for each feature a feature vector digital signal representing the position of the image data of the feature in an N-dimensional space, N being an integer and said space being defined by a plurality of reference vector signals each of which is an eigenvector of a training set of images of like features; and modifying the digital signal image data of each feature to normalize the shape of each feature thereby to reduce its deviation from a predetermined standard shape of said feature, which step is carried out before generating the feature vector signal for each feature, wherein the step of locating within the digital signal image the position of at least one predetermined feature employs: a first technique to provide a coarse estimation of position, and a second, different, technique to improve upon the coarse estimation.
Claim 6
Independent Claim
187 words
A method of processing an image represented by an array of digital signals, said method comprising the steps of: locating within the image array of digital signals the position of at least one predetermined feature; extracting image data from said image array of digital signals representing each said feature; generating for each feature a feature vector digital signal representing the position of the image data of the feature in an N-dimensional space, N being an integer and said space being defined by a plurality of reference vector signals each of which is an eigenvector of a training set of images of like features; and modifying the digital signal image data of each feature to normalize the shape of each feature thereby to reduce its deviation from a predetermined standard shape of said feature, which step is carried out before generating the feature vector signal for each feature, wherein the step of locating within the digital signal image the position of at least one predetermined feature employs: a first technique to provide a coarse estimation of position, and a second, different, technique to improve upon the coarse estimation.
Claim 7
Dependent Claim
14 words
A method according to claim 3 wherein the second technique uses a deformable template.
Claim 8
Dependent Claim
60 words
A method according to claim 1 in which the training set of digital signal images of like features are modified to normalize the shape of each of the training set of digital signal images to reduce deviation from a predetermined standard shape of features and subsequently the reference vector eigenvectors of the training set of digital signal images are generated.
Claim 9
Dependent Claim
57 words
A method according to claim 1 wherein said locating step comprises: locating a portion of the digital signal image by determining parameters of a closed curve arranged to lie adjacent a plurality of edge features of the digital signal image, said curve being constrained to exceed a minimum curvature and to have a minimum length compatible therewith.
Claim 10
Dependent Claim
36 words
A method as in claim 6 in which the curve is initially generated proximate the plurality of edge features of the digital signal image, and subsequently interactively re-generated to reduce its distance from said edge features.
Claim 11
Dependent Claim
25 words
A method according to claim 6 in which the located portion of the digital signal image is a face or a head of a person.
Claim 12
Independent Claim
196 words
A method of verifying the identity of the user of a data carrier, said method comprising the steps of: generating a digital signal facial image of the user; receiving the data carrier and reading therefrom identification data signals; performing on the digital signal facial image the steps of: (i) locating within the digital signal image the position of at least one predetermined feature; (ii) extracting digital signal image data from said image representing each said feature; (iii) generating for each feature a feature vector signal representing the position of the image data of the feature in an N-dimensional space, N being an integer and said space being defined by a plurality of reference vectors signals each of which is an eigenvector of a training set of images of like features; and (iv) modifying the digital signal image data of each feature to normalize the shape of each feature thereby to reduce its deviation from a predetermined standard shape of said feature, which step is carried out before generating the feature vector for each feature; comparing data signals representing each feature vector with the identification data signals; and generating a verification signal in dependence upon the comparison.
Claim 13
Independent Claim
196 words
A method of verifying the identity of the user of a data carrier, said method comprising the steps of: generating a digital signal facial image of the user; receiving the data carrier and reading therefrom identification data signals; performing on the digital signal facial image the steps of: (i) locating within the digital signal image the position of at least one predetermined feature; (ii) extracting digital signal image data from said image representing each said feature; (iii) generating for each feature a feature vector signal representing the position of the image data of the feature in an N-dimensional space, N being an integer and said space being defined by a plurality of reference vectors signals each of which is an eigenvector of a training set of images of like features; and (iv) modifying the digital signal image data of each feature to normalize the shape of each feature thereby to reduce its deviation from a predetermined standard shape of said feature, which step is carried out before generating the feature vector for each feature; comparing data signals representing each feature vector with the identification data signals; and generating a verification signal in dependence upon the comparison.
Claim 14
Dependent Claim
199 words
Apparatus for verifying the identity of the user of a data carrier comprising: means for generating a digital signal facial image of the user; means for receiving the data carrier and reading therefrom identification data signals; means for performing on the digital signal facial image the steps of: (i) locating within the digital signal image and position of at least one predetermined feature; (ii) extracting digital signal image data from said image representing each said feature; (iii) generating for each feature a feature vector signal representing the position of the image data of the feature in an N-dimensional space, N being an integer and said space being defined by a plurality of reference vector signals each of which is an eigenvector of a training set of images of like features; and (iv) modifying the digital signal image data of each feature to normalize the shape of each feature thereby to reduce its deviation from a predetermined standard shape of said feature, which step is carried out before calculating the feature vector for each feature; and means for comparing data signals representing each feature vector with the identification data signals and generating a verification signal in dependence upon the comparison.
Claim 15
Dependent Claim
199 words
Apparatus for verifying the identity of the user of a data carrier comprising: means for generating a digital signal facial image of the user; means for receiving the data carrier and reading therefrom identification data signals; means for performing on the digital signal facial image the steps of: (i) locating within the digital signal image and position of at least one predetermined feature; (ii) extracting digital signal image data from said image representing each said feature; (iii) generating for each feature a feature vector signal representing the position of the image data of the feature in an N-dimensional space, N being an integer and said space being defined by a plurality of reference vector signals each of which is an eigenvector of a training set of images of like features; and (iv) modifying the digital signal image data of each feature to normalize the shape of each feature thereby to reduce its deviation from a predetermined standard shape of said feature, which step is carried out before calculating the feature vector for each feature; and means for comparing data signals representing each feature vector with the identification data signals and generating a verification signal in dependence upon the comparison.
Claim 16
Dependent Claim
33 words
Apparatus as in claim 10 in which the means for generating a digital signal facial image of the user comprises a video camera, the output of which is connected to an AD convertor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-02-16 | 2001-08-18 | 2002-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-02-16 | 2005-08-18 | 2006-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-02-16 | 2009-08-18 | 2010-02-17 | $7700.00 | Window Closed / Lapsed |