Function initFilterLuma0

source/NTSC.cpp:1125–1134

Butterworth Lowpass digital filter Filter Order: 2 -> poles for low pass ===========================================================================

// Filter Order: 2 -> poles for low pass
//===========================================================================
static real initFilterLuma0 (real z)
{
	static real x[LUMA_ZEROS + 1] = { 0,0,0 };
	static real y[LUMA_POLES + 1] = { 0,0,0 };

	x[0] = x[1];   x[1] = x[2];   x[2] = z / LUMA_GAIN;
	y[0] = y[1];   y[1] = y[2];   y[2] = x[0] + x[2] + (2.f*x[1]) + (LUMA_0*y[0]) + (LUMA_1*y[1]);

	return y[2];
}

// Butterworth Lowpass digital filter
// Filter Order: 2 -> poles for low pass