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fftc_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 fftc_im(double im, double tfr_im, double **tfi_im, int n, int flag)
	{
	const extern struct g_mode M;
	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 (im, nbr_lin, nbr_col);
	if (err != 0)
	{
	fprintf(stderr, "ERROR: when splitting input image\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+inbr_col)] = im[i][j];
	image_FT[2(j+inbr_col)+1] = 0.0;
	}

	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[2k] / ((double)(nbr_lin nbr_col));
	tfi_im[i][j] = image_FT[2k+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);
	}
	}


	}