opencv/cv.go
func Sobel(src, dst *IplImage, xorder, yorder, aperture_size int) {
	C.cvSobel(unsafe.Pointer(src), unsafe.Pointer(dst),
		C.int(xorder), C.int(yorder),
		C.int(aperture_size),
	)
}
func Sobel(src, dst *IplImage, xorder, yorder, aperture_size int) {
	C.cvSobel(unsafe.Pointer(src), unsafe.Pointer(dst),
		C.int(xorder), C.int(yorder),
		C.int(aperture_size),
	)
}
//CVAPI(void)  cvCanny( const CvArr* image, CvArr* edges, double threshold1,
//                      double threshold2, int  aperture_size CV_DEFAULT(3) );
/* Calculates the first, second, third, or mixed image derivatives using an
* extended Sobel operator.  */