'\" te
.\" Copyright (c) 2007, Sun Microsystems, Inc.  All Rights Reserved 
.TH mlib_ImageFourierTransform 3MLIB "2 Mar 2007" "SunOS 5.11" "mediaLib Library Functions"
.SH NAME
mlib_ImageFourierTransform \- Fourier transform
.SH SYNOPSIS
.LP
.nf
cc [ \fIflag\fR... ] \fIfile\fR... \fB-lmlib\fR [ \fIlibrary\fR... ]
#include <mlib.h>

\fBmlib_status\fR \fBmlib_ImageFourierTransform\fR(\fBmlib_image *\fR\fIdst\fR,
     \fBconst mlib_image *\fR\fIsrc\fR, \fBmlib_fourier_mode\fR \fImode\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBmlib_ImageFourierTransform()\fR function performs a two-dimensional Fourier transformation. The source and destination images must be the same type and the same size. The data type of the images can be \fBMLIB_BYTE\fR, \fBMLIB_SHORT\fR, \fBMLIB_USHORT\fR, \fBMLIB_INT\fR, \fBMLIB_FLOAT\fR, or \fBMLIB_DOUBLE\fR. The height and width of the images must be some positive power of 2 (but they do not have to be equal).
.sp
.LP
They can have 1 or 2 channels. If the source image has just one channel the imaginary parts are assumed to be zero. If the destination image has just one channel, then it is assumed that the imaginary parts of the output can be discarded. But in case both source and destination images are one-channel images, then \fBMLIB_FAILURE\fR is returned.
.sp
.LP
The predefined modes used in the image Fourier transform function are as follows:
.sp

.sp
.TS
tab();
cw(2.75i) cw(2.75i) 
lw(2.75i) lw(2.75i) 
.
ModeDescription
_
\fBMLIB_DFT_SCALE_NONE\fRForward DFT without scaling
\fBMLIB_DFT_SCALE_MXN\fRForward DFT with scaling of \fB1/(M*N)\fR
\fBMLIB_DFT_SCALE_SQRT\fRForward DFT with scaling of \fB1/sqrt(M*N)\fR
\fBMLIB_IDFT_SCALE_NONE\fRInverse DFT without scaling
\fBMLIB_IDFT_SCALE_MXN\fRInverse DFT with scaling of \fB1/(M*N)\fR
\fBMLIB_IDFT_SCALE_SQRT\fRInverse DFT with scaling of \fB1/sqrt(M*N)\fR
.TE

.SH PARAMETERS
.sp
.LP
The function takes the following arguments:
.sp
.ne 2
.mk
.na
\fB\fIdst\fR\fR
.ad
.RS 8n
.rt  
Pointer to destination image.
.RE

.sp
.ne 2
.mk
.na
\fB\fIsrc\fR\fR
.ad
.RS 8n
.rt  
Pointer to source image.
.RE

.sp
.ne 2
.mk
.na
\fB\fImode\fR\fR
.ad
.RS 8n
.rt  
Mode of the transform.
.RE

.SH RETURN VALUES
.sp
.LP
The function returns \fBMLIB_SUCCESS\fR if successful. Otherwise it returns \fBMLIB_FAILURE\fR.
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Interface StabilityCommitted
_
MT-LevelMT-Safe
.TE

.SH SEE ALSO
.sp
.LP
\fBattributes\fR(5)