# NAME

get_matrix_inverse_dct - Computes the inverse discrete cosine transform (DCT) of a matrix
# SYNOPSIS

#include "wrap_fftw/wrap_fftw.h"
Example compile flags (system dependent):
-DLINUX_X86_64 -DLINUX_X86_64_OPTERON -DGNU_COMPILER
-I/home/kobus/include
-L/home/kobus/misc/load/linux_x86_64_opteron -L/usr/lib/x86_64-linux-gnu
-lKJB -lfftw3 -lgsl -lgslcblas -ljpeg -lSVM -lstdc++ -lpthread -lSLATEC -lg2c -lacml -lacml_mv -lblas -lg2c -lncursesw
int get_matrix_inverse_dct
(
Matrix **output_mpp,
const Matrix *input_mp
);

# DESCRIPTION

This routine computes the inverse discrete cosine transform (DCT) of a
matrix.
The first argument is the adress of the target matrix. If the target matrix
itself is null, then a matrix of the appropriate size is created. If the
target matrix is the wrong size, it is resized. Finally, if it is the right
size, then the storage is recycled, as is.
# RETURNS

NO_ERROR on success, and ERROR on failure, with an error message being
set.
# NOTE

This routine simply wraps the appropriate fftw library functions for
convenient use with our our data structures. The fftw library can also be
used directly in conjunction with the kjb_library by including fftw3.h
(the makefile builder should know where to find everthing). This can be
preferable in some cases where one wants to exploit the tuning mechanism
from that library, and cut down on overhead. However, for ocasional use,
the savings won't be very great.
# WARNING

The default behaviour of this routine is to inherits fftw's normalization
strategy which is to return unnormalized transforms. This means that
taking the transform, and then inverting, requires division by
N=num_cols*num_rows. This behaviour can be changed using the
set_fftw_style() function. Currently the style setting of
FFTW_MATLAB_STYLE is not valid with DCT because it has not yet been
implemented (on the TODO list).
# REFERENCES

http://www.fftw.org/
# DISCLAIMER

This software is not adequatedly tested. It is recomended that
results are checked independantly where appropriate.
# AUTHOR

Kobus Barnard
# DOCUMENTER

Kobus Barnard
# SEE ALSO

set_fftw_style
,
get_matrix_dct
,
get_matrix_dft
,
get_matrix_inverse_dft
,
get_vector_dft