0

How I can restore image by means of fftw3 if I have full fourier spectrum of image for restoring? I have tried to transmute fftwf_complex **arr1 to fftwf_complex *arr2 and put it into the fftwf_plan_dft_c2r_2d, but on output was a unexpected noise but not the expected image.

int size_s = 1030;

fftwf_complex **ifftshifted -  1030x1030 pixels image

fftwf_complex *result_prefin = fftwf_malloc(size_s * size_s * sizeof(fftwf_complex));
for (int i = 0; i < size_s; i  ) {
   for (int j = 0; j < size_s; j  ) {
     result_prefin[j   i * size_s][0] = ifftshifted[i][j][0];  //real 
     result_prefin[j   i * size_s][1] = ifftshifted[i][j][1];  //imaginary
   }
}

Make a inverse fast fourier transform:

floaf *result_ifft2 = malloc(size_s * size_s * sizeof(float));

fftwf_plan plan = fftwf_plan_dft_c2r_2d(size_s, size_s, result_prefin, result_ifft2, FFTW_ESTIMATE);
fftwf_execute(plan);
fftwf_destroy_plan(plan);

Recreating the image for saving to TIFF:

float size_dim_fft = size_s*size_s;

float **result_ifft2_normal = (d_vector *)malloc(size_s * sizeof(float*));

for (int i = 0, offset = 0; i < size_s; i  ) {
   result_ifft2_normal[i] = (d_vector)malloc(size_s * sizeof(d_type));

   for (int j = 0; j < size_s; j  ) {
      result_ifft2_normal[i][j] = result_ifft2[j   offset]/size_dim_fft;
   }

   offset  = size_s;
}

Use FFTSHIFT because the spectrum was put into the IFFT function with IFFTSHIFT: 

float **result_fftshift = NULL;
shift2d(&result_ifft2_normal, &result_fftshift, 1030, 1030, 0);

write_tiff("restored.tif",result_fftshift,1030,1030);
4

0 回答 0