void i_radnoise(i_img *im,i_img_dim xo,i_img_dim yo,double rscale,double ascale);
void i_turbnoise(i_img *im,double xo,double yo,double scale);
void i_gradgen(i_img *im, int num, i_img_dim *xo, i_img_dim *yo, i_color *ival, int dmeasure);
void i_radnoise(i_img *im,i_img_dim xo,i_img_dim yo,double rscale,double ascale);
void i_turbnoise(i_img *im,double xo,double yo,double scale);
void i_gradgen(i_img *im, int num, i_img_dim *xo, i_img_dim *yo, i_color *ival, int dmeasure);