robot36/yuv.c

#include "yuv.h"

uint8_t yuv_clamp(float x)
{
	float tmp = x < 0.0 ? 0.0 : x;
	return tmp > 255.0 ? 255.0 : tmp;
}

uint8_t R_YUV(uint8_t Y, uint8_t U, uint8_t V)
{
	(void)U;
	return yuv_clamp(0.003906 * ((298.082 * (Y - 16.0)) + (408.583 * (V - 128))));
}
uint8_t G_YUV(uint8_t Y, uint8_t U, uint8_t V)
{
	return yuv_clamp(0.003906 * ((298.082 * (Y - 16.0)) + (-100.291 * (U - 128)) + (-208.12 * (V - 128))));
}
uint8_t B_YUV(uint8_t Y, uint8_t U, uint8_t V)
{
	(void)V;
	return yuv_clamp(0.003906 * ((298.082 * (Y - 16.0)) + (516.411 * (U - 128))));
}

uint8_t Y_RGB(uint8_t R, uint8_t G, uint8_t B)
{
	return yuv_clamp(16.0 + (0.003906 * ((65.738 * R) + (129.057 * G) + (25.064 * B))));
}
uint8_t V_RGB(uint8_t R, uint8_t G, uint8_t B)
{
	return yuv_clamp(128.0 + (0.003906 * ((112.439 * R) + (-94.154 * G) + (-18.285 * B))));
}
uint8_t U_RGB(uint8_t R, uint8_t G, uint8_t B)
{
	return yuv_clamp(128.0 + (0.003906 * ((-37.945 * R) + (-74.494 * G) + (112.439 * B))));
}