C09EDF computes the inverse two-dimensional multi-level discrete wavelet transform (DWT). This routine reconstructs data from (possibly filtered or otherwise manipulated) wavelet transform coefficients calculated by
C09ECF from an original input matrix. The initialization routine
C09ABF must be called first to set up the DWT options.
C09EDF performs the inverse operation of
C09ECF. That is, given a set of wavelet coefficients, computed by
C09ECF using a DWT as set up by the initialization routine
C09ABF, on a real matrix,
$A$, C09EDF will reconstruct
$A$. The reconstructed matrix is referred to as
$B$ in the following since it will not be identical to
$A$ when the DWT coefficients have been filtered or otherwise manipulated prior to reconstruction. If the original input matrix is level
$0$, then it is possible to terminate reconstruction at a higher level by specifying fewer than the number of levels used in the call to
C09ECF. This results in a partial reconstruction.
None.
If on entry
${\mathbf{IFAIL}}={\mathbf{0}}$ or
${-{\mathbf{1}}}$, explanatory error messages are output on the current error message unit (as defined by
X04AAF).
The accuracy of the wavelet transform depends only on the floating point operations used in the convolution and downsampling and should thus be close to machine precision.
None.