opencv/cxcore.go
func SubScalarRev(value Scalar, src, dst *IplImage) {
	SubScalarWithMaskRev(value, src, dst, nil)
}
func SubScalarRev(value Scalar, src, dst *IplImage) {
	SubScalarWithMaskRev(value, src, dst, nil)
}
// Calculates the per-element difference between a scalar and an array.
//   dst = value - src