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fftcc_im.c
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Sat, Jan 4, 03:04

fftcc_im.c
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#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#include<fonction.h>
#include<constant.h>
#include<dimension.h>
#include<structure.h>
void fftcc_im(double **r_im, double **i_im, double **tfr_im, double **tfi_im, int n, int flag)
{
const extern struct g_mode M;
register int i, j, k;
int err, isign, nbr_lin, nbr_col;
int ndim, nn[2];
double *image_FT;
nbr_lin = n;
nbr_col = n;
if (flag == -1)
{
err = (int)split_image (r_im, nbr_lin, nbr_col);
if (err != 0)
{
fprintf(stderr, "\nFATAL ERROR: when splitting input image\n\n");
exit(-1);
}
err = (int)split_image (i_im, nbr_lin, nbr_col);
if (err != 0)
{
NPRINTF(stderr, "\nFATAL ERROR: when splitting input image\n\n");
exit(-1);
}
}
/* FAST FOURIER TRANSFORM OF THE IMAGE */
image_FT = (double *) malloc (2 * nbr_lin * nbr_col * sizeof(double));
for (i = 0; i < nbr_lin; i++)
for (j = 0; j < nbr_col; j++)
{
image_FT[2*(j+i*nbr_col)] = r_im[i][j];
image_FT[2*(j+i*nbr_col)+1] = i_im[i][j];
}
ndim = 2;
isign = -flag;
nn[0] = nbr_lin;
nn[1] = nbr_col;
fft(image_FT - 1, nn - 1, ndim, isign);
for (k = 0; k < nbr_lin*nbr_col; k++)
{
i = k / nbr_col;
j = k - i * nbr_col;
if (flag == 1)
{
tfr_im[i][j] = image_FT[2*k];
tfi_im[i][j] = image_FT[2*k+1];
}
else if (flag == -1)
{
tfr_im[i][j] = image_FT[2*k] / ((double)(nbr_lin * nbr_col));
tfi_im[i][j] = image_FT[2*k+1] / ((double)(nbr_lin * nbr_col));
}
}
free(image_FT);
/* SPLITS RESULTS TO HAVE ORIGIN AT CENTER OF IMAGE
*/
if (flag == 1)
{
err = (int)split_image(tfr_im, nbr_lin, nbr_col);
if (err != 0)
{
NPRINTF(stderr, "\a\nFATAL ERROR: problem to split results\n\n");
exit(-1);
}
err = (int)split_image(tfi_im, nbr_lin, nbr_col);
if (err != 0)
{
NPRINTF(stderr, "\a\nFATAL ERROR: problem to split results\n\n");
exit(-1);
}
}
}

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