C09FDF computes the inverse three-dimensional multi-level discrete wavelet transform (IDWT). This routine reconstructs data from (possibly filtered or otherwise manipulated) wavelet transform coefficients calculated by C09FCF
from an original input array. The initialization routine C09ACF
must be called first to set up the IDWT options.
C09FDF performs the inverse operation of C09FCF
. That is, given a set of wavelet coefficients, computed by C09FCF
using a DWT as set up by the initialization routine C09ACF
, on a real three-dimensional array,
, C09FDF will reconstruct
. The reconstructed array is referred to as
in the following since it will not be identical to
when the DWT coefficients have been filtered or otherwise manipulated prior to reconstruction. If the original input array is level
, then it is possible to terminate reconstruction at a higher level by specifying fewer than the number of levels used in the call to C09FCF
. This results in a partial reconstruction.
If on entry
, 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.