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cv_cpsf.c
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Fri, Dec 27, 13:37

cv_cpsf.c
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#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#include"fonction.h"
#include "lt.h"
/*
JPK - OMP - 20 Mai 97
Convolve an image by a circular gaussien PSF of FWHM=seeing
calls crea_filtre(seeing,pixel-size,filter,n)
*/
void cv_cpsf(double **im,
int nx, int ny,
double xmin, double xmax, double ymin, double ymax,
double seeing)
{
register int i, j;
int n, N, err;
double scalex, scaley;
double **z, **tfr_z, **tfi_z, **filter, **tfr_f, **tfi_f;
double **r_conv, **i_conv, **tfr_conv, **tfi_conv;
/* compute pixel scale ---------------------------------------*/
scalex = (xmax - xmin) / (nx - 1);
scaley = (ymax - ymin) / (ny - 1);
if ( fabs(scalex - scaley) > 1e-5)
{
fprintf(stderr, "WARNING: pixel is not a square\n");
}
/* include the image in a larger 2^N image ---------------------*/
N = (int) ceil(log(((double)Max(nx, ny))) / log(2.));
n = (int) pow(2., ((double)N));
z = (double **) alloc_square_double(n, n);
for (i = 0; i < n; i++)
for (j = 0; j < n; j++)
{
if ((i < nx) && (j < ny))
z[i][j] = im[i][j];
else
z[i][j] = 0.;
}
/* compute filter -------------------------------------------*/
filter = (double **) alloc_square_double(n, n);
crea_filtre(seeing, (scalex + scaley) / 2., filter, n);
/* Compute Fourrier Transform -------------------------------*/
tfr_z = (double **) alloc_square_double(n, n);
tfi_z = (double **) alloc_square_double(n, n);
fftc_im(z, tfr_z, tfi_z, n, 1);
free_square_double(z, n);
tfr_f = (double **) alloc_square_double(n, n);
tfi_f = (double **) alloc_square_double(n, n);
fftc_im(filter, tfr_f, tfi_f, n, 1);
free_square_double(filter, n);
tfr_conv = (double **) alloc_square_double(n, n);
tfi_conv = (double **) alloc_square_double(n, n);
ic_product(tfr_z, tfi_z, tfr_f, tfi_f, tfr_conv, tfi_conv, n, n);
free_square_double(tfr_z, n);
free_square_double(tfi_z, n);
free_square_double(tfr_f, n);
free_square_double(tfi_f, n);
r_conv = (double **) alloc_square_double(n, n);
i_conv = (double **) alloc_square_double(n, n);
fftcc_im(tfr_conv, tfi_conv, r_conv, i_conv, n, -1);
free_square_double(tfr_conv, n);
free_square_double(tfi_conv, n);
err = (int) split_image(r_conv, n, n);
if (err != 0)
{
fprintf(stderr, "\nFATAL ERROR: when splitting input image\n");
exit(-1);
}
/* copy results into the original image --------------------*/
for (i = 0; i < nx; i++)
for (j = 0; j < ny; j++)
im[i][j] = r_conv[i][j];
free_square_double(r_conv, n);
free_square_double(i_conv, n);
}

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