US5481269A
Expired / Lapsed
US
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General frame wavelet classifier
Assignee: Northrop Grumman Corp
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Filing: 1994-05-27
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Granted: 1996-01-02
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Expires: 2014-05-27
Abstract
Abstract A classifier employing general frame wavelets for improving target recognition while decreasing computational intensity is disclosed. A wavelet selection means compares a portion of a time dependent input signal from a receiver with a set of sample wavelets, each wavelet being bandpass limited, locally supported, and mean zero, and selects a prototype wavelet resembling the input portion. A resolving means expands the prototype wavelet onto a basis of wavelet functions having variations in scale and delay, and resolves the input signal onto the basis of functions. A regionpass filter identifies a region from a grid of resolved coefficients that contains features of a target from the input signal and discards coefficients outside the region. A separability filter passes select coefficients from a scale band within the identified region where separability among known targets is high. A comparator compares the selected coefficients with an exemplar of known targets to indicate a recognition of the target.
Inventors
- 👤 Scott A. Imhoff
- 👤 Martin G. Woolfson
- 👤 Giora A. Bendor
- 👤 Guy W. Cheesman, III
- 👤 James R. Brinsley
- 👤 Martin M. Morici
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:36
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/41; G01S7/411; G06; G06F; G06F17/00; G06F17/10; G06F17/14; G06V; G06V10/00; G06V10/20; G06V10/255; G06V10/40; G06V10/42; G06V10/431; G06F2218/00; G06F2218/08
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
251 words
A classifier for recognizing features of a target in a received signal, comprising: means for selecting a prototype wavelet corresponding in amplitude and phase per unit of time to a portion of said received signal; means for resolving said received signal onto a basis of wavelet functions in a wavelet domain by calculating inner product transform coefficients between said received signal and each of said wavelet functions, said wavelet functions corresponding to variations in scale and delay for said prototype wavelet, said variations in scale and delay exceeding a frame condition for said prototype wavelet and said basis, said frame condition enabling an inverse wavelet transform of said calculated inner product transform coefficients to converge on said received signal; a regionpass filter for identifying a target region of said basis and for passing said inner product transform coefficients within said target region, said target region including said target features in the received signal; a separability filter coupled to said regionpass filter for passing select inner product transform coefficients in said target region, said select inner product transform coefficients being a scale band within said target region and having a separability between known targets exceeding the separability in other scale bands within said target region, a scale band defined by a set of inner product transform coefficients having a common scale variable; and a comparator coupled to said separability filter for comparing said select inner product transform coefficients to an exemplar, said comparison indicating a recognition of said features of the target.
Claim 2
Dependent Claim
251 words
A classifier for recognizing features of a target in a received signal, comprising: means for selecting a prototype wavelet corresponding in amplitude and phase per unit of time to a portion of said received signal; means for resolving said received signal onto a basis of wavelet functions in a wavelet domain by calculating inner product transform coefficients between said received signal and each of said wavelet functions, said wavelet functions corresponding to variations in scale and delay for said prototype wavelet, said variations in scale and delay exceeding a frame condition for said prototype wavelet and said basis, said frame condition enabling an inverse wavelet transform of said calculated inner product transform coefficients to converge on said received signal; a regionpass filter for identifying a target region of said basis and for passing said inner product transform coefficients within said target region, said target region including said target features in the received signal; a separability filter coupled to said regionpass filter for passing select inner product transform coefficients in said target region, said select inner product transform coefficients being a scale band within said target region and having a separability between known targets exceeding the separability in other scale bands within said target region, a scale band defined by a set of inner product transform coefficients having a common scale variable; and a comparator coupled to said separability filter for comparing said select inner product transform coefficients to an exemplar, said comparison indicating a recognition of said features of the target.
Claim 3
Dependent Claim
13 words
The classifier of claim 1, wherein said basis of wavelet functions is orthonormal.
Claim 4
Dependent Claim
17 words
The classifier of claim 1, wherein said prototype wavelet is bandpass limited, locally supported, and mean zero.
Claim 5
Dependent Claim
13 words
The classifier of claim 1, wherein said basis of wavelet functions is overcomplete.
Claim 6
Dependent Claim
15 words
The classifier of claim 4, wherein said overcomplete basis of wavelet functions is general frame.
Claim 7
Dependent Claim
44 words
The classifier of claim 5, wherein said frame condition is critical frame, said critical frame indicating the variation for scale and delay for said prototype wavelet where a number of said inner product calculations is a minimum for said inverse wavelet transform to converge.
Claim 8
Dependent Claim
55 words
The classifier of claim 6, wherein said critical frame for said prototype wavelet h m ,n (t) occurs at h m ,n (t)=(1/√a o m )h(t/a o m -nb o ) when a o is a minimum for said inverse wavelet transform to converge, b o being a real constant, m and n being integers.
Claim 9
Dependent Claim
35 words
The classifier of claim 6, wherein said critical frame for said prototype wavelet is determined using a non-continuous function within a complement of a space of continuous functions within Hilbert space for said input signal.
Claim 10
Dependent Claim
16 words
The classifier of claim 8, wherein said non-continuous function within Hilbert space is a square wave.
Claim 11
Dependent Claim
33 words
The classifier of claim 1, wherein said comparator shifts a delay variable of said select inner product transform coefficients to increase a correlation between said select inner product transform coefficients and said exemplar.
Claim 12
Dependent Claim
13 words
The classifier of claim 1, wherein said comparison is a Pearson's r correlation.
Claim 13
Dependent Claim
222 words
A preclassifier for discriminating features of a target in a received signal, comprising: means for selecting a prototype wavelet corresponding in amplitude and phase per unit of time to a portion of said received signal; means for resolving said received signal onto a basis of wavelet functions in a wavelet domain by calculating inner product transform coefficients between said received signal and each of said wavelet functions, said wavelet functions corresponding to variations in scale and delay for said prototype wavelet, said variations in scale and delay exceeding a frame condition for said prototype wavelet and said basis, said frame condition enabling an inverse wavelet transform of said calculated inner product transform coefficients to converge on said received signal; a regionpass filter for identifying a target region of said basis and for passing said inner product transform coefficients within said target region, said target region including said target features in the received signal; and a separability filter coupled to said regionpass filter for passing select inner product transform coefficients in said target region, said select inner product transform coefficients being a scale band within said target region and having a separability between known targets exceeding the separability in other scale bands within said target region, a scale band defined by a set of inner product transform coefficients having a common scale variable.
Claim 14
Dependent Claim
222 words
A preclassifier for discriminating features of a target in a received signal, comprising: means for selecting a prototype wavelet corresponding in amplitude and phase per unit of time to a portion of said received signal; means for resolving said received signal onto a basis of wavelet functions in a wavelet domain by calculating inner product transform coefficients between said received signal and each of said wavelet functions, said wavelet functions corresponding to variations in scale and delay for said prototype wavelet, said variations in scale and delay exceeding a frame condition for said prototype wavelet and said basis, said frame condition enabling an inverse wavelet transform of said calculated inner product transform coefficients to converge on said received signal; a regionpass filter for identifying a target region of said basis and for passing said inner product transform coefficients within said target region, said target region including said target features in the received signal; and a separability filter coupled to said regionpass filter for passing select inner product transform coefficients in said target region, said select inner product transform coefficients being a scale band within said target region and having a separability between known targets exceeding the separability in other scale bands within said target region, a scale band defined by a set of inner product transform coefficients having a common scale variable.
Claim 15
Dependent Claim
13 words
The preclassifier of claim 12, wherein said basis of wavelet functions is orthonormal.
Claim 16
Dependent Claim
17 words
The preclassifier of claim 12, wherein said prototype wavelet is bandpass limited, locally supported, and mean zero.
Claim 17
Dependent Claim
13 words
The preclassifier of claim 12, wherein said basis of wavelet functions is overcomplete.
Claim 18
Dependent Claim
15 words
The preclassifier of claim 15, wherein said overcomplete basis of wavelet functions is general frame.
Claim 19
Dependent Claim
44 words
The preclassifier of claim 16, wherein said frame condition is critical frame, said critical frame indicating the variation for scale and delay for said prototype wavelet where a number of said inner product calculations is a minimum for said inverse wavelet transform to converge.
Claim 20
Dependent Claim
55 words
The preclassifier of claim 17, wherein said critical frame for said prototype wavelet h m ,n (t) occurs at h m , n(t)=(1/√a o m )h(t/a o m -nb o ) when a o is a minimum for said inverse wavelet transform to converge, b o being a real constant, m and n being integers.
Claim 21
Dependent Claim
35 words
The preclassifier of claim 17, wherein said critical frame for said prototype wavelet is determined using a non-continuous function within a complement of a space of continuous functions within Hilbert space for said input signal.
Claim 22
Dependent Claim
16 words
The preclassifier of claim 19, wherein said non-continuous function within Hilbert space is a square wave.
Claim 23
Dependent Claim
155 words
A filter for passing select inner product transform coefficients from a resolution of a received signal onto a basis of wavelet functions in a wavelet domain, said wavelet functions corresponding to variations in scale and delay for a prototype wavelet, said select inner product transform coefficients including features of a received target, comprising: a regionpass filter for identifying a target region of said basis and for passing said inner product transform coefficients within said target region, said target region including said features of the received target; and a separability filter coupled to said regionpass filter for passing select inner product transform coefficients in said target region, said select inner product transform coefficients being a scale band within said target region and having a separability between known targets exceeding the separability in other scale bands within said target region, a scale band defined by a set of inner product transform coefficients having a common scale variable.
Claim 24
Dependent Claim
155 words
A filter for passing select inner product transform coefficients from a resolution of a received signal onto a basis of wavelet functions in a wavelet domain, said wavelet functions corresponding to variations in scale and delay for a prototype wavelet, said select inner product transform coefficients including features of a received target, comprising: a regionpass filter for identifying a target region of said basis and for passing said inner product transform coefficients within said target region, said target region including said features of the received target; and a separability filter coupled to said regionpass filter for passing select inner product transform coefficients in said target region, said select inner product transform coefficients being a scale band within said target region and having a separability between known targets exceeding the separability in other scale bands within said target region, a scale band defined by a set of inner product transform coefficients having a common scale variable.
Claim 25
Dependent Claim
35 words
The filter of claim 21, further comprising an amplitude filter coupled to said separability filter for passing a portion of said select inner product transform coefficients, said portion having an amplitude exceeding a predetermined value.
Claim 26
Dependent Claim
44 words
The filter of claim 21, wherein said regionpass filter identifies a target region by correlating said inner product transform coefficients occurring inside a sample region in a scale-delay plane of said wavelet domain with said inner product transform coefficients occurring outside said sample region.
Claim 27
Dependent Claim
20 words
The filter of claim 23, wherein said regionpass filter adjusts a size of said sample region to decrease said correlation.
Claim 28
Dependent Claim
24 words
The filter of claim 23, wherein said regionpass filter shifts a location of said sample region in said scale-delay plane to decrease said correlation.
Claim 29
Dependent Claim
13 words
The filter of claim 23, wherein said correlation is a Pearson's r correlation.
Claim 30
Dependent Claim
13 words
The filter of claim 23, wherein said sample region has an ellipsoidal shape.
Claim 31
Independent Claim
233 words
A method for classifying features of a target in a received signal, comprising the steps of: (a) selecting a prototype wavelet corresponding in amplitude and phase per unit of time to a portion of said received signal; (b) resolving said received signal onto a basis of wavelet functions in a wavelet domain by calculating inner product transform coefficients between said received signal and each of said wavelet functions, said wavelet functions corresponding to variations in scale and delay for said prototype wavelet, said variations in scale and delay exceeding a frame condition for said prototype wavelet and said basis, said frame condition enabling an inverse wavelet transform of said calculated inner product transform coefficients to converge on said received signal; (c) identifying a target region of said basis, said target region including said target features in the received signal; (d) passing said inner product transform coefficients within said target region; (e) passing select inner product transform coefficients in said target region, said select inner product transform coefficients being a scale band within said target region and having a separability between known targets exceeding the separability in other scale bands within said target region, a scale band defined by a set of inner product transform coefficients having a common scale variable; and (f) comparing said select inner product transform coefficients to an exemplar, said comparison indicating a recognition of said features of the target.
Claim 32
Independent Claim
233 words
A method for classifying features of a target in a received signal, comprising the steps of: (a) selecting a prototype wavelet corresponding in amplitude and phase per unit of time to a portion of said received signal; (b) resolving said received signal onto a basis of wavelet functions in a wavelet domain by calculating inner product transform coefficients between said received signal and each of said wavelet functions, said wavelet functions corresponding to variations in scale and delay for said prototype wavelet, said variations in scale and delay exceeding a frame condition for said prototype wavelet and said basis, said frame condition enabling an inverse wavelet transform of said calculated inner product transform coefficients to converge on said received signal; (c) identifying a target region of said basis, said target region including said target features in the received signal; (d) passing said inner product transform coefficients within said target region; (e) passing select inner product transform coefficients in said target region, said select inner product transform coefficients being a scale band within said target region and having a separability between known targets exceeding the separability in other scale bands within said target region, a scale band defined by a set of inner product transform coefficients having a common scale variable; and (f) comparing said select inner product transform coefficients to an exemplar, said comparison indicating a recognition of said features of the target.
Claim 33
Independent Claim
209 words
A method for preclassifying features of a target in a received signal, comprising the steps of: (a) selecting a prototype wavelet corresponding in amplitude per unit of time to a portion of said received signal; (b) resolving said received signal onto a basis of wavelet functions in a wavelet domain by calculating inner product transform coefficients between said received signal and each of said wavelet functions, said wavelet functions corresponding to variations in scale and delay for said prototype wavelet, said variations in scale and delay exceeding a frame condition for said prototype wavelet and said basis, said frame condition enabling an inverse wavelet transform of said calculated inner product transform coefficients to converge on said received signal; (c) identifying a target region of said basis, said target region including said target features in the received signal; (d) passing said inner product transform coefficients within said target region; and (e) passing select inner product transform coefficients in said target region, said select inner product transform coefficients being a scale band within said target region and having a separability between known targets exceeding the separability in other scale bands within said target region, a scale band defined by a set of inner product transform coefficients having a common scale variable.
Claim 34
Independent Claim
209 words
A method for preclassifying features of a target in a received signal, comprising the steps of: (a) selecting a prototype wavelet corresponding in amplitude per unit of time to a portion of said received signal; (b) resolving said received signal onto a basis of wavelet functions in a wavelet domain by calculating inner product transform coefficients between said received signal and each of said wavelet functions, said wavelet functions corresponding to variations in scale and delay for said prototype wavelet, said variations in scale and delay exceeding a frame condition for said prototype wavelet and said basis, said frame condition enabling an inverse wavelet transform of said calculated inner product transform coefficients to converge on said received signal; (c) identifying a target region of said basis, said target region including said target features in the received signal; (d) passing said inner product transform coefficients within said target region; and (e) passing select inner product transform coefficients in said target region, said select inner product transform coefficients being a scale band within said target region and having a separability between known targets exceeding the separability in other scale bands within said target region, a scale band defined by a set of inner product transform coefficients having a common scale variable.
Claim 35
Independent Claim
133 words
A method for passing select inner product transform coefficients from a resolution of a received signal onto a basis of wavelet functions in a wavelet domain, said wavelet functions corresponding to variations in scale and delay for a prototype wavelet, said select inner product transform coefficients including features of a received target, comprising the steps of: (a) identifying a target region of said basis, said target region including said received target features; and (b) passing select inner product transform coefficients in said target region, said select inner product transform coefficients being a scale band within said target region and having a separability between known targets exceeding the separability in other scale bands within said target region, a scale band defined by a set of inner product transform coefficients having a common scale variable.
Claim 36
Independent Claim
133 words
A method for passing select inner product transform coefficients from a resolution of a received signal onto a basis of wavelet functions in a wavelet domain, said wavelet functions corresponding to variations in scale and delay for a prototype wavelet, said select inner product transform coefficients including features of a received target, comprising the steps of: (a) identifying a target region of said basis, said target region including said received target features; and (b) passing select inner product transform coefficients in said target region, said select inner product transform coefficients being a scale band within said target region and having a separability between known targets exceeding the separability in other scale bands within said target region, a scale band defined by a set of inner product transform coefficients having a common scale variable.
Claim 37
Dependent Claim
36 words
The method of passing select inner product transform coefficients of claim 30, further comprising the step of: (c) filtering a portion of said select inner product transform coefficients having an amplitude less than a predetermined value.
Claim 38
Dependent Claim
85 words
The method of passing select inner product transform coefficients of claim 30, wherein said identifying step comprises the steps of: (i) selecting a sample region in a scale-delay plane of said wavelet domain; (ii) correlating said inner product transform coefficients occurring inside said sample region with said inner product transform coefficients occurring outside said sample region; (iii) adjusting a size of said sample region to decrease said correlation; and (iv) shifting a location of said sample region in said scale-delay plane to decrease said correlation.
References Cited (Backward Citations)
US5027658A
Cited
US5000183A
Cited
US5124930A
Cited
US5056066A
Cited
US5247448A
Cited
US5420891A
Cited
US5417215A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1999-01-01 | 1999-07-03 | 2000-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-01 | 2003-07-03 | 2004-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-01 | 2007-07-03 | 2008-01-02 | $7700.00 | Window Closed / Lapsed |