/**
* im_video_test:
* @im: write image here
* @brightness: brightness setting
* @error: set this to make the function return an error
*
* Make a test video image. Set @error to trigger an error.
*
* Returns: 0 on success, -1 on error
*/
int
im_video_test( IMAGE *im, int brightness, int error )
{
if( error ) {
im_error( "im_video_test", "%s", _( "error requested" ) );
return( -1 );
}
else
return( im_gaussnoise( im, 720, 576, brightness, 20 ) );
}
/**
* im_addgnoise:
* @in: input image
* @out: output image
* @sigma: standard deviation of noise
*
* Add gaussian noise with mean 0 and variance sigma to @in.
* The noise is generated by averaging 12 random numbers,
* see page 78, PIETGEN, 1989.
*
* See also: im_gaussnoise().
*
* Returns: 0 on success, -1 on error
*/
int
im_addgnoise( IMAGE *in, IMAGE *out, double sigma )
{
IMAGE *t;
if( !(t = im_open_local( out, "im_addgnoise", "p" )) ||
im_gaussnoise( t, in->Xsize, in->Ysize, 0, sigma ) ||
im_add( in, t, out ) )
return( -1 );
return( 0 );
}
/* Call im_gaussnoise via arg vector.
*/
static int
gaussnoise_vec( im_object *argv )
{
int xsize = *((int *) argv[1]);
int ysize = *((int *) argv[2]);
double mean = *((double *) argv[3]);
double sigma = *((double *) argv[4]);
if( im_gaussnoise( argv[0], xsize, ysize, mean, sigma ) )
return( -1 );
return( 0 );
}
int
im_addgnoise( IMAGE *in, IMAGE *out, double sigma ){
#define FUNCTION_NAME "im_addgnoise"
if( im_piocheck( in, out ))
return -1;
{
int i;
IMAGE **temps= IM_ARRAY( out, in-> Bands, IMAGE* );
IMAGE *joined_temps= im_open_local( out, FUNCTION_NAME ": joined_temps", "p" );
if( ! temps || ! joined_temps || im_open_local_array( out, temps, in-> Bands, FUNCTION_NAME ": temps", "p" ))
return -1;
for( i= 0; i < in-> Bands; ++i )
if( im_gaussnoise( temps[i], in-> Xsize, in-> Ysize, 0.0, sigma ))
return -1;
return im_gbandjoin( temps, joined_temps, in-> Bands ) || im_add( in, joined_temps, out );
}
#undef FUNCTION_NAME
}