Cepstral method and system for detecting/classifying objects from air-based or space-based images
AssigneeLockheed Martin Corporation
InventorJoe V. Petty
Life of this patent
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Abstract
A system and method for detecting and/or classifying an obscured discrete cultural object and/or an obscured replicated object using image data from an optical, infrared or synthetic aperture radar imaging system is disclosed. Generally, the method and system of the present invention are directed to performing a cepstral analysis on the image data to attentuate the corruption signal in the image data and/or to enhance the discrete cultural object signal and/or the replicated object signature, and displaying an output of the cepstral analysis in the pixel and/or the spatial quefrency domain to detect and/or classify the discrete cultural object and/or the replicated object.
Claims37
A method for detecting at least a first cultural object using at least first image data from one of a first optical, a first infrared and a first synthetic aperture radar image, wherein the first image data includes signals corresponding to noise and to at least a first cultural object convolved with corruption, said method comprising the steps of:
- processing the first image data from a pixel domain into the spatial quefrency domain to produce from said corruption and at least the first cultural object signals separable cepstral coefficients corresponding to at least the first cultural object and corruption signals in the spatial quefrency domain;
- processing in the spatial quefrency domain at least a first cepstral coefficient corresponding to the corruption signal to attenuate at least a portion of the corruption signal, wherein at least a first cepstral coefficient corresponding to at least a portion of at least the first cultural object signal remains;
- and
- processing at least the first cepstral coefficient corresponding to at least the portion of the first cultural object signal in the spatial quefrency domain to obtain at least the portion of at least the first cultural object signal corresponding to at least the first cultural object in the pixel domain, wherein at least a portion of the first cultural object is displayable.
A method for detecting at least a first replicated object using at least first image data from one of a first optical, a first infrared and a first synthetic aperture radar image, the first replicated object comprising a plurality of objects arranged in a first array, wherein the first image data includes signals corresponding to corruption and at least a first replicated signature corresponding to at least the first replicated object, said method comprising the steps of:
- processing the first image data from a pixel domain into a spatial quefrency domain to produce separable cepstral coefficients corresponding to at least a first amplification factor, the first replicated object signature and corruption signal in the spatial quefrency domain;
- processing in the spatial quefrency domain at least a first cepstral coefficient corresponding to the corruption signal to attenuate at least a portion of the corruption signal, wherein at least a first cepstral coefficient corresponding to at least a portion of the first replicated object signature remains;
- and
- processing at least the first cepstral coefficients corresponding to at least the portion of the first replicated object signature and the first amplification factor to obtain an enhanced first replicated object signature corresponding to at least the portion of the first replicated object signature in the pixel domain, wherein at least a portion of the first replicated object is displayable in the pixel domain.
A method for detecting at least a first cultural object using at least first image data from one of a first optical, a first infrared and a first synthetic aperture radar image, wherein the first image data includes signals corresponding to at least the first cultural object convolved with corruption, said method comprising the steps of:
- applying a two-dimensional Fourier transform to the first image data in a pixel domain to at least transform the first image data into at least a first discrete term, wherein the first discrete term comprises a product of a spatial frequency of at least the first cultural object signal and a spatial frequency of the corruption signal in the spatial frequency domain;
- applying in the spatial frequency domain a complex logarithm to at least the first discrete term, wherein the output of the complex logarithm comprises a discrete sum, said discrete sum comprising a sum of the complex logarithm of the spatial frequency of at least the first cultural object signal and the complex logarithm of the spatial frequency of the corruption signal;
- applying an inverse two-dimensional Fourier transform to the discrete sum to transform the discrete sum into cepstral coefficients corresponding to at least the first cultural object signal and the corruption signal in a spatial quefrency domain;
- and
- processing in the spatial quefrency domain at least a first cepstral coefficient corresponding to the corruption signal to attenuate at least a portion of the corruption signal, wherein at least a first cepstral coefficient corresponding to at least a portion of the first cultural object remains.
A method for detecting at least a first replicated object using first image data from one of a first optical, a first infrared and a first synthetic aperture radar image, the first replicated object comprising a plurality of objects arranged in a first pattern, wherein the first image data includes signals corresponding to corruption and at least a first replicated object signature corresponding to at least the first replicated object, said method comprising the steps of:
- applying a two-dimensional Fourier transform to the first image data in a pixel domain to transform the first image data into at least a first replicated term, wherein the first replicated term comprises a product of a first amplification factor and a spatial frequency of each of the first replicated object signature and the corruption signal in a spatial frequency domain;
- applying in the spatial frequency domain a complex logarithm to at least the first replicated term, wherein the output of the complex logarithm comprises a replicated sum, said replicated sum comprising a sum of the complex logarithm of the first amplification factor, the complex logarithm of the spatial frequency of the first replicated object signature and the complex logarithm of the spatial frequency of the corruption signal;
- and
- applying an inverse two-dimensional Fourier transform to the replicated sum to transform the replicated sum into the cepstral coefficients corresponding to the first replicated object signature, the first amplification factor and the corruption signal in a spatial quefrency domain, wherein at least the first replicated object is detectable.
A method for detecting at least one of a first cultural object and a first replicated object using at least first image data from one of a first optical, a first infrared and a first synthetic aperture radar image, the first replicated object comprising replicated objects, wherein the first image data in a pixel domain includes signals corresponding to noise and corruption and at least one of a first cultural object signal corresponding to the first cultural object and a first replicated object signature corresponding to at least the first replicated object, said method comprising the steps of:
- performing a cepstral analysis on at least the first image data to at least one of attenuate a portion of the corruption signal and enhance at least one of the first cultural object signal and the first replicated object signature;
- and
- detecting at least one of the first cultural object and the first replicated object in at least one of a spatial quefrency domain and the pixel domain.
A system for detecting at least one of a first cultural object and a first replicated object using at least first image data from one of a first optical, a first infrared and a first synthetic aperture radar image, the first replicated object comprising a plurality of objects arranged in a pattern, wherein the first image data in a pixel domain includes signals corresponding to noise and corruption and at least one of a first cultural object signal corresponding to the first cultural object and a first replicated object signature corresponding to at least the first replicated object, said system comprising:
- means for performing a cepstral analysis on at least said first image data to at least one of attenuate a portion of the corruption signal and enhance at least the first replicated object signature;
- and
- means for displaying an output of said means for performing in at least one of the pixel domain and a spatial quefrency domain to detect at least one of the first cultural object and the first replicated object.
Dependencies are inferred from the claim text.