synthetize_lpf Method (SynWTFilter)

In This Topic

Reconstructs the output signal by the synthesis filter, recomposing the low-pass and high-pass input signals in one output signal. This method performs the upsampling and fitering with the low pass first filtering convention.

The input low-pass (high-pass) signal resides in the lowSig array. The index of the first sample to filter (i.e. that will generate the first (second) output sample). is given by lowOff (highOff). 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 low-pass (high-pass) input signal can be interleaved with other signals in the same lowSig (highSig) array, and this is determined by the lowStep (highStep) argument. This means that the first sample of the low-pass (high-pass) input signal is lowSig[lowOff] (highSig[highOff]), the second is lowSig[lowOff+lowStep] (highSig[highOff+highStep]), the third is lowSig[lowOff+2*lowStep] (highSig[highOff+2*highStep]), and so on. Therefore if lowStep (highStep) 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 lowSig (highSig), without having to copy the data, in this case the lowStep (highStep) argument should be the line width of the low-pass (high-pass) signal.

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

Syntax

Visual Basic
C#

'Declaration
 
Public MustOverride Sub synthetize_lpf( _
   ByVal lowSig As Object, _
   ByVal lowOff As Integer, _
   ByVal lowLen As Integer, _
   ByVal lowStep As Integer, _
   ByVal highSig As Object, _
   ByVal highOff As Integer, _
   ByVal highLen As Integer, _
   ByVal highStep As Integer, _
   ByVal outSig As Object, _
   ByVal outOff As Integer, _
   ByVal outStep As Integer _
)

public abstract void synthetize_lpf( 
   object lowSig,
   int lowOff,
   int lowLen,
   int lowStep,
   object highSig,
   int highOff,
   int highLen,
   int highStep,
   object outSig,
   int outOff,
   int outStep
)

Parameters

lowSig: This is the array that contains the low-pass input signal. It must be of the correct type (e.g., it must be int[] if getDataType() returns TYPE_INT).
lowOff: This is the index in lowSig of the first sample to filter.
lowLen: This is the number of samples in the low-pass input signal to filter.
lowStep: This is the step, or interleave factor, of the low-pass input signal samples in the lowSig array. See above.
highSig: This is the array that contains the high-pass input signal. It must be of the correct type (e.g., it must be int[] if getDataType() returns TYPE_INT).
highOff: This is the index in highSig of the first sample to filter.
highLen: This is the number of samples in the high-pass input signal to filter.
highStep: This is the step, or interleave factor, of the high-pass input signal samples in the highSig array. See above.
outSig: This is the array where the output signal is placed. It must be of the same type as lowSig and it should be long enough to contain the output signal.
outOff: This is the index in outSig of the element where to put the first output sample.
outStep: This is the step, or interleave factor, of the output samples in the outSig array. See above.

Reference

SynWTFilter Class
SynWTFilter Members