func (c *ColorM) ChangeHSV(hueTheta float64, saturationScale float32, valueScale float32) *ColorM {
	sin, cos := math.Sincos(hueTheta)
	s32, c32 := float32(sin), float32(cos)
	c = c.Concat(rgbToYCbCr)
	c = c.Concat(&ColorM{
		body: []float32{
			1, 0, 0, 0,
			0, c32, s32, 0,
			0, -s32, c32, 0,
			0, 0, 0, 1,
		},
	})
	s := saturationScale
	v := valueScale
	c = c.Scale(v, s*v, s*v, 1)
	c = c.Concat(yCbCrToRgb)
	return c
}
func (c *ColorM) ChangeHSV(hueTheta float64, saturationScale float32, valueScale float32) *ColorM {
	sin, cos := math.Sincos(hueTheta)
	s32, c32 := float32(sin), float32(cos)
	c = c.Concat(rgbToYCbCr)
	c = c.Concat(&ColorM{
		body: []float32{
			1, 0, 0, 0,
			0, c32, s32, 0,
			0, -s32, c32, 0,
			0, 0, 0, 1,
		},
	})
	s := saturationScale
	v := valueScale
	c = c.Scale(v, s*v, s*v, 1)
	c = c.Concat(yCbCrToRgb)
	return c
}
// ChangeHSV changes HSV (Hue-Saturation-Value) elements.
// hueTheta is a radian value to ratate hue.
// saturationScale is a value to scale saturation.
// valueScale is a value to scale value (a.k.a. brightness).
//
// This conversion uses RGB to/from YCrCb conversion.