void iso_diffusion_denoising(image *x, image *y,
float kappa, int iters)
{
/* Function of removing noise from pictures
*
* image x : input picture
* image y : help picture of same size
* float kappa : denoising constant
* int iters : number of itereations
*/
// Initialize local variables
int i; int j; int iter;
float ** tmp;
int m = (*x).m; int n = (*x).n;
float ** data0 = (*x).image_data;
float ** data1 = (*y).image_data;
// Fill top and bottom edge
for (i=0; i<m; i++)
{
data1[i][0] = data0[i][0];
data1[i][n-1] = data0[i][n-1];
}
// Fill left and right edges
for (i=1; i<n-1; i++) // skip corners
{
data1[0][i] = data0[0][i];
data1[m-1][i] = data0[m-1][i];
}
for (iter=0; iter<iters; iter++)
{
// Fill interior
for (i=1; i<m-1; i++)
{
for (j=1; j<n-1; j++)
{
data1[i][j] = data0[i][j] +kappa*(data0[i-1][j]
+data0[i][j-1] -4*data0[i][j] +data0[i][j+1]
+data0[i+1][j]);
}
}
// Swap links between data0 and data1
tmp = data0;
data0 = data1;
data1 = tmp;
}
(*x).image_data = data0;
(*y).image_data = data1;
return;
}
int main(int argc, char *argv[])
{
int m, n, c, iters;
float kappa;
image u, u_bar;
unsigned char *image_chars;
char *input_jpeg_filename, *output_jpeg_filename;
/* read from command line: kappa, iters, input_jpeg_filename, output_jpeg_filename */
kappa = atof(argv[1]);
iters = atoi(argv[2]);
input_jpeg_filename = argv[3];
output_jpeg_filename = argv[4];
import_JPEG_file(input_jpeg_filename, &image_chars, &m, &n, &c);
allocate_image (&u, m, n);
allocate_image (&u_bar, m, n);
convert_jpeg_to_image (image_chars, &u);
iso_diffusion_denoising (&u, &u_bar, kappa, iters);
convert_image_to_jpeg (&u_bar, image_chars);
export_JPEG_file(output_jpeg_filename, image_chars, m, n, c, 75);
deallocate_image (&u);
deallocate_image (&u_bar);
return 0;