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GrapeCity.Documents.Imaging Assembly / GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.analysis Namespace / AnWTFilter Class
Fields Methods

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    AnWTFilter Class Members
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    The following tables list the members exposed by AnWTFilter.

    Public Fields
     NameDescription
    Public FieldThe prefix for wavelet filter options: 'F'  
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    Public Methods
     NameDescription
    Public MethodFilters the input signal by this analysis filter, decomposing it in a low-pass and a high-pass signal. This method performs the filtering and the subsampling with the high pass first filtering convention.

    The input signal resides in the inSig array. The index of the first sample to filter (i.e. that will generate the first high-pass output sample) is given by inOff. The number of samples to filter is given by inLen. This array must be of the same type as the one for which the particular implementation works with (which is returned by the getDataType() method).

    The input signal can be interleaved with other signals in the same inSig array, and this is determined by the inStep argument. This means that the first sample of the input signal is inSig[inOff], the second is inSig[inOff+inStep], the third is inSig[inOff+2*inStep], and so on. Therefore if inStep is 1 there is no interleaving. This feature allows to filter columns of a 2-D signal, when it is stored in a line by line order in inSig, without having to copy the data, in this case the inStep argument should be the line width.

    The low-pass output signal is placed in the lowSig array. The lowOff and lowStep arguments are analogous to the inOff and inStep ones, but they apply to the lowSig array. The lowSig array must be long enough to hold the low-pass output signal.

    The high-pass output signal is placed in the highSig array. The highOff and highStep arguments are analogous to the inOff and inStep ones, but they apply to the highSig array. The highSig array must be long enough to hold the high-pass output signal.

     
    Public MethodFilters the input signal by this analysis filter, decomposing it in a low-pass and a high-pass signal. This method performs the filtering and the subsampling with the low pass first filtering convention.

    The input signal resides in the inSig array. The index of the first sample to filter (i.e. that will generate the first low-pass output sample) is given by inOff. The number of samples to filter is given by inLen. This array must be of the same type as the one for which the particular implementation works with (which is returned by the getDataType() method).

    The input signal can be interleaved with other signals in the same inSig array, and this is determined by the inStep argument. This means that the first sample of the input signal is inSig[inOff], the second is inSig[inOff+inStep], the third is inSig[inOff+2*inStep], and so on. Therefore if inStep is 1 there is no interleaving. This feature allows to filter columns of a 2-D signal, when it is stored in a line by line order in inSig, without having to copy the data, in this case the inStep argument should be the line width.

    This method also allows to apply the analysis wavelet filter by parts in the input signal using an overlap and thus producing the same coefficients at the output. The tailOvrlp argument specifies how many samples in the input signal, before the first one to be filtered, can be used for overlap. Then, the filter instead of extending the input signal will use those samples to calculate the first output samples. The argument tailOvrlp can be 0 for no overlap, or some value that provides partial or full overlap. There should be enough samples in the input signal, before the first sample to be filtered, to support the overlap. The headOvrlp provides the same functionality but at the end of the input signal. The inStep argument also applies to samples used for overlap. This overlap feature can be used for line-based wavelet transforms (in which case it will only be used when filtering the columns) or for overlapping block-based wavelet transforms (in which case it will be used when filtering lines and columns).

    The low-pass output signal is placed in the lowSig array. The lowOff and lowStep arguments are analogous to the inOff and inStep ones, but they apply to the lowSig array. The lowSig array must be long enough to hold the low-pass output signal.

    The high-pass output signal is placed in the highSig array. The highOff and highStep arguments are analogous to the inOff and inStep ones, but they apply to the highSig array. The highSig array must be long enough to hold the high-pass output signal.

     
    Public MethodSee: GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.IWaveletFilter.getAnHighNegSupport  
    Public MethodSee: GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.IWaveletFilter.getAnHighPosSupport  
    Public MethodSee: GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.IWaveletFilter.getAnLowNegSupport  
    Public MethodSee: GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.IWaveletFilter.getAnLowPosSupport  
    Public MethodSee: GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.IWaveletFilter.getDataType  
    Public MethodReturns the type of filter used according to the FilterTypes interface.  
    Public MethodReturns the time-reversed high-pass synthesis waveform of the filter, which is the high-pass filter. This is the time-reversed impulse response of the high-pass synthesis filter. It is used to calculate the L2-norm of the synthesis basis functions for a particular subband (also called energy weight).

    The returned array may not be modified (i.e. a reference to the internal array may be returned by the implementation of this method).

     
    Public MethodReturns the equivalent high-pass synthesis waveform of a cascade of filters, given the syhthesis waveform of the previous stage. This is the result of upsampling 'in' by 2, and concolving it with the high-pass synthesis waveform of the filter. The length of the returned signal is 2*in_l+hp_l-2, where in_l is the length of 'in' and 'hp_l' is the lengthg of the high-pass synthesis filter.

    The length of the high-pass synthesis filter is getSynHighNegSupport()+getSynHighPosSupport().

     
    Public MethodSee: GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.IWaveletFilter.getImplType  
    Public MethodReturns the time-reversed low-pass synthesis waveform of the filter, which is the low-pass filter. This is the time-reversed impulse response of the low-pass synthesis filter. It is used to calculate the L2-norm of the synthesis basis functions for a particular subband (also called energy weight).

    The returned array may not be modified (i.e. a reference to the internal array may be returned by the implementation of this method).

     
    Public MethodReturns the equivalent low-pass synthesis waveform of a cascade of filters, given the syhthesis waveform of the previous stage. This is the result of upsampling 'in' by 2, and concolving it with the low-pass synthesis waveform of the filter. The length of the returned signal is 2*in_l+lp_l-2, where in_l is the length of 'in' and 'lp_l' is the lengthg of the low-pass synthesis filter.

    The length of the low-pass synthesis filter is getSynLowNegSupport()+getSynLowPosSupport().

     
    Public Methodstatic (Shared in Visual Basic)Returns the parameters that are used in this class and implementing classes. It returns a 2D String array. Each of the 1D arrays is for a different option, and they have 3 elements. The first element is the option name, the second one is the synopsis, the third one is a long description of what the parameter is and the fourth is its default value. The synopsis or description may be 'null', in which case it is assumed that there is no synopsis or description of the option, respectively. Null may be returned if no options are supported.  
    Public MethodSee: GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.IWaveletFilter.getSynHighNegSupport  
    Public MethodSee: GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.IWaveletFilter.getSynHighPosSupport  
    Public MethodSee: GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.IWaveletFilter.getSynLowNegSupport  
    Public MethodSee: GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.IWaveletFilter.getSynLowPosSupport  
    Public MethodSee: GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.IWaveletFilter.isReversible  
    Public MethodSee: GrapeCity.Documents.Imaging.jpeg.jj2000.j2k.wavelet.IWaveletFilter.isSameAsFullWT(System.Int32,System.Int32,System.Int32)  
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