实验2-彩色空间转换

1.实验目的：

完成将得到的RGB文件转换为YUV文件的程序，并用YUV Viewer播放器观看，验证是否正确。

2.实验原理：

亮度和色差信号的构成如下
Y=0.2990R+0.5870G+0.1140B
R-Y=0.7010R-0.5870G-0.1140B
B-Y=-0.2990R-0.5870G+0.8860B
进行归一化后，有
U=-0.1684R-0.3316G+0.5B
V=0.5R-0.4187G-0.0813B

3.实验过程

#include<stdio.h>
#include<stdlib.h>
static float r0299[256],g0587[256],b0114[256],r01684[256],g03316[256],b05[256],r05[256],g04187[256],b00813[256];
void Table()
{
for(int i=0;i<256;i++) r0299[i]=0.299i;
for(int i=0;i<256;i++) g0587[i]=0.587i;
for(int i=0;i<256;i++) b0114[i]=0.114i;
for(int i=0;i<256;i++) r01684[i]=0.1684i;
for(int i=0;i<256;i++) g03316[i]=0.3316i;
for(int i=0;i<256;i++) b05[i]=0.5i;
for(int i=0;i<256;i++) r05[i]=0.5i;
for(int i=0;i<256;i++) g04187[i]=0.4187i;
for(int i=0;i<256;i++) b00813[i]=0.0813*i;
}
int RGB2YUV(int height,int width,unsigned char *RGB__buffer,unsigned char *YUV__buffer)
{

Table();
unsigned char *b_buffer,*g_buffer,*r_buffer;
unsigned char *Y_buffer,*U_buffer,*V_buffer;
unsigned char *u_buffer,*v_buffer;
unsigned char *pu_up1,*pu_up2,*pv_up1,*pv_up2;
Y_buffer=YUV__buffer;
U_buffer=YUV__buffer+height*width;
V_buffer=YUV__buffer+height*width*5/4;
u_buffer=new unsigned char[height*width];
v_buffer=new unsigned char[height*width];
pu_up1=u_buffer;
pu_up2=u_buffer+width;
pv_up1=v_buffer;
pv_up2=v_buffer+width;
b_buffer=RGB__buffer;
g_buffer=RGB__buffer+1;
r_buffer=RGB__buffer+2;
unsigned char *pu_buffer,*pv_buffer;
pu_buffer=u_buffer;
pv_buffer=v_buffer;
for(int i=0;i<height;i++)
{
	for(int j=0;j<width;j++)
	{
		if(r0299[*r_buffer]+g0587[*g_buffer]+b0114[*b_buffer]<0)
			*Y_buffer=(unsigned char)0;
		else
			if(r0299[*r_buffer]+g0587[*g_buffer]+b0114[*b_buffer]>255)
				*Y_buffer=(unsigned char)255;
			else *Y_buffer=unsigned char (r0299[*r_buffer]+g0587[*g_buffer]+b0114[*b_buffer]);
		if(-r01684[*r_buffer]-g03316[*g_buffer]+b05[*b_buffer]<-128)
			*pu_buffer=(unsigned char)0;
		else
			if(-r01684[*r_buffer]-g03316[*g_buffer]+b05[*b_buffer]>128)
				*pu_buffer=(unsigned char)255;
			else *pu_buffer=unsigned char(-r01684[*r_buffer]-g03316[*g_buffer]+b05[*b_buffer]+128);
		if(r05[*r_buffer]-g04187[*g_buffer]-b00813[*b_buffer]<-128)
			*pv_buffer=(unsigned char)0;
		else
			if(r05[*r_buffer]-g04187[*g_buffer]-b00813[*b_buffer]>128)
				*pv_buffer=(unsigned char)255;
			else *pv_buffer=unsigned char(r05[*r_buffer]-g04187[*g_buffer]-b00813[*b_buffer]+128);
		Y_buffer++;
		pu_buffer++;
		pv_buffer++;
		r_buffer+=3;
		g_buffer+=3;
		b_buffer+=3;
	}
}
for(int i=0;i<height/2;i++)
{
	for(int j=0;j<width/2;j++)
	{
		*U_buffer=(*pu_up1+*(pu_up1+1)+*pu_up2+*(pu_up2+1))/4;
		*V_buffer=(*pv_up1+*(pv_up1+1)+*pv_up2+*(pv_up2+1))/4;
		U_buffer++;
		V_buffer++;
		pu_up1+=2;
		pu_up2+=2;
		pv_up1+=2;
		pv_up2+=2;
	}
	if(i!=height/2)
	{
		pu_up1+=width;
		pu_up2+=width;
		pv_up1+=width;
		pv_up2+=width;
	}
}
delete[] u_buffer;
delete[] v_buffer;
return 0;

}

结果：

RGB文件成功用YUV打开