YUV422与RGB互相转换（经验证在IPNC与PC上都可以）
前一段时间在DM8168中进行颜色空间的转换，在网上找了些程序，自己也根据网上的改了下，由于能力问题，实在是不好意思说做了好几天才弄出来， 主要是因为YUV<—>RGB有各种各样的转换公式。在多次的实验修改后，终于找到了对的公式，共享出来，以便需要的人选择。
在监控系统中大多采用YUV的颜色空间，原因不说了，网上搜YUV转RGB各种介绍。
在TI的视频英语达芬奇系列中（这里只测试了DVR、IPNC），
采用如下公式：
yCbCr<-->rgb
Y’ = 0.257*R‘ + 0.504*G‘ + 0.098*B‘ + 16
Cb‘ = -0.148*R‘ - 0.291*G‘ + 0.439*B‘ + 128
Cr‘ = 0.439*R‘ - 0.368*G‘ - 0.071*B‘ + 128
R‘ = 1.164*(Y’-16) + 1.596*(Cr‘-128)
G‘ = 1.164*(Y’-16) - 0.813*(Cr‘-128) - 0.392*(Cb‘-128)
B‘ = 1.164*(Y’-16) + 2.017*(Cb‘-128)
转换效果图如下
第一幅是原图YUV，第二幅是转为RGB后存为bmp，反转是因为BMP图像是从最下面一行开始存取的原因，最下面一副是转回YUV的图像。
代码如下，代码中YUV采用YUYVYUYV的格式，RGB为RGBRGBRGB.....
http://download.csdn.net/detail/guo8113/7318031(代码下载)
1 #ifndef _RGB2YUV__
2 #define _RGB2YUV__
3 #include <iostream>
4 using namespace std;
5
6 #define TUNE(r) ( r < 0 ? 0 : (r > 255 ? 255 : r) )
7
8 static int RGB_Y[256];
9 static int RGBR_V[256];
10 static int RGBG_U[256];
11 static int RGBG_V[256];
12 static int RGBB_U[256];
13
14
15 static int YUVY_R[256];
16 static int YUVY_G[256];
17 static int YUVY_B[256];
18
19 static int YUVU_R[256];
20 static int YUVU_G[256];
21 static int YUVU_B[256];
22
23 static int YUVV_R[256];
24 static int YUVV_G[256];
25 static int YUVV_B[256];
26
27 static int coff_rv[256];
28 static int coff_gu[256];
29 static int coff_gv[256];
30 static int coff_bu[256];
31
32 //直接采用公式浮点计算方式
33 //仅RGB2YUV采用了查表法，所以有一部分表是没有用到的
34 void InitTable()
35 {
36 int i;
37 for(i = 0;i<256;i++)
38 {
39 //初始化表,放大256倍
40 RGB_Y[i] = 298 * (i - 16);
41 RGBR_V[i] = 408 * (i - 128);
42 RGBG_U[i] = 100 * (128- i);
43 RGBG_V[i]= 208*(128-i);
44 RGBB_U[i] =517 * (i - 128);
45 //y=0.257*r+0.504*g+0.098*b+16
46 //u = -0.148*r - 0.291*g + 0.439*b + 128
47 //0.439*r - 0.368*g - 0.071*b + 128
48 YUVY_R[i]=66*i;
49 YUVY_G[i]=129*i;
50 YUVY_B[i]=25*i;
51 YUVU_R[i]=-38*i;
52 YUVU_G[i]=-74*i;
53 YUVU_B[i]=112*i;
54 YUVV_R[i]=112*i;
55 YUVV_G[i]=-94*i;
56 YUVV_B[i]=-18*i;
57 /*所用公式(此公式不适用)
58 *pRGB = (unsigned char)(1.0*y + 8 + 1.402*(v-128)); pRGB++; // r
59 *pRGB = (unsigned char)(1.0*y - 0.34413*(u-128) - 0.71414*(v-128)); pRGB++; // g
60 *pRGB = (unsigned char)(1.0*y + 1.772*(u-128) + 0); pRGB++ ;
61 */
62 coff_rv[i] = (8+1.402*(i-128))*256;
63 coff_gu[i] = -0.34413*(i-128)*256;
64 coff_gv[i] = -0.71414*(i-128)*256;
65 coff_bu[i] = 1.772*(i-128)*256;
66
67 /*应该使用如下公式：
68 Y’ = 0.257*R‘ + 0.504*G‘ + 0.098*B‘ + 16
69 Cb‘ = -0.148*R‘ - 0.291*G‘ + 0.439*B‘ + 128
70 Cr‘ = 0.439*R‘ - 0.368*G‘ - 0.071*B‘ + 128(标红的两组公式是可逆的转换)
71 R‘ = 1.164*(Y’-16) + 1.596*(Cr‘-128)
72 G‘ = 1.164*(Y’-16) - 0.813*(Cr‘-128) - 0.392*(Cb‘-128)
73 B‘ = 1.164*(Y’-16) + 2.017*(Cb‘-128)
74 */
75 }
76 }
77
78 void YUV2RGB422(unsigned char *pRGB, unsigned char *pYUV,int size)
79 {
80 unsigned char y, u, v,y1;
81 int r,g,b;
82 unsigned int i=0;
83 unsigned int loop = size>>1;
84 while(loop-- >0)
85 {
86
87 y = *pYUV; pYUV++;
88 u = *pYUV; pYUV++;
89 y1 = *pYUV;pYUV++;
90 v = *pYUV; pYUV++;
91
92 r = 1.164*(y-16) + 1.596*(v-128);
93 g = 1.164*(y-16) - 0.813*(v-128) - 0.392*(u-128);
94 b = 1.164*(y-16) + 2.017*(u-128);
95
96 *pRGB = TUNE(r);pRGB++;
97 *pRGB = TUNE(g);pRGB++;
98 *pRGB = TUNE(b);pRGB++;
99
100 r = 1.164*(y1-16) + 1.596*(v-128);
101 g = 1.164*(y1-16) - 0.813*(v-128) - 0.392*(u-128);
102 b = 1.164*(y1-16) + 2.017*(u-128);
103 *pRGB = TUNE(r);pRGB++;
104 *pRGB = TUNE(g);pRGB++;
105 *pRGB = TUNE(b);pRGB++;
106 }
107
108 }
109
110 //size 为图片的大小
111 void RGB2YUV422(unsigned char *pRGB, unsigned char *pYUV,int size)
112 {
113 unsigned char r,g,b,u,v,u1,v1,r1,g1,b1;
114 //unsigned char *YUVBuff;
115 //unsigned char* p;
116 //p = YUVBuff;//
117 int loop = size/2;
118 int i;
119 for( i=0;i<loop;i++)
120 {
121 r = *pRGB; pRGB++;
122 g = *pRGB; pRGB++;
123 b = *pRGB; pRGB++;
124 r1 = *pRGB; pRGB++;
125 g1 = *pRGB; pRGB++;
126 b1 = *pRGB; pRGB++;
127
128 //new method --- right
129 int y = ((YUVY_R[r] + YUVY_G[g] + YUVY_B[b] + 128) >> 8) +16;
130 u = ((YUVU_R[r] + YUVU_G[g] + YUVU_B[b] + 128) >> 8) + 128;
131 v = ((YUVV_R[r] + YUVV_G[g] + YUVV_B[b] + 128) >> 8) + 128;
132 int y1 = ((YUVY_R[r1] + YUVY_G[g1] + YUVY_B[b1] + 128) >> 8)+16;
133 u1 = ((YUVU_R[r1] + YUVU_G[g1] + YUVU_B[b1] + 128) >> 8) + 128;
134 v1 = ((YUVV_R[r1] + YUVV_G[g1] + YUVV_B[b1] + 128) >> 8) + 128;
135
136 *pYUV++ = TUNE(y);
137 *pYUV++ =(TUNE(u)+TUNE(u1))>>1;
138 *pYUV++ = TUNE(y1);
139 *pYUV++ = TUNE(v);
140 }
141
142 }
143
144 void inline Yuv2RgbPixel(unsigned char y,unsigned char u,unsigned char v, unsigned char* rgbPixel)
145 {
146 int r = (RGB_Y[y] + RGBR_V[v] + 128) >> 8;
147 int g = ((RGB_Y[y] + RGBG_V[v] +RGBG_U[u]+ 128)>>8 );
148 int b = ((RGB_Y[y] + RGBB_U[u]+128 )>>8);
149 *rgbPixel=TUNE(r);rgbPixel++;
150 *rgbPixel=TUNE(g);rgbPixel++;
151 *rgbPixel=TUNE(b);
152 }
153
154 void YUV2RGB(unsigned char *pRGB, unsigned char *pYUV,int size)//444
155 {
156 unsigned char y, u, v;
157
158 for(int i=0;i<size;i++)
159 {
160 y = *pYUV; pYUV++;
161 u = *pYUV; pYUV++;
162 v = *pYUV; pYUV++;
163
164 Yuv2RgbPixel(y,u,v,pRGB);
165 pRGB += 3;
166 }
167
168 }
169
170 void inline Rgb2YuvPiexl(unsigned char r,unsigned char g,unsigned char b,unsigned char* pYUV)
171 {
172 int y = ((YUVY_R[r] + YUVY_G[g] + YUVY_B[b] + 128) >> 8) + 16;
173 int u = ((YUVU_R[r] + YUVU_G[g] + YUVU_B[b] + 128) >> 8) + 128;
174 int v = ((YUVV_R[r] + YUVV_G[g] + YUVV_B[b] + 128) >> 8) + 128;
175 *pYUV = TUNEY(y);pYUV++;
176 //*pYUV = u < 0 ? 0 : (u > 255 ? 255 : u);pYUV++;
177 *pYUV =TUNE(u);pYUV++;
178 *pYUV = TUNE(v);
179 }
180
181 void RGB2YUV(unsigned char *pRGB, unsigned char *pYUV,int size)
182 {
183 unsigned char r,g,b,y,u,v;
184 for(int i=0;i<size;i++)
185 {
186 r = *pRGB; pRGB++;
187 g = *pRGB; pRGB++;
188 b = *pRGB; pRGB++;
189 Rgb2YuvPiexl(r,g,b,pYUV);
190 pYUV +=3;
191
192 }
193 }
194 #endif
http://www.61ic.com/Article/DaVinci/TMS320DM81x/201408/52651.html
http://blog.csdn.net/xgmiao/article/details/23512021
http://www.cnblogs.com/jck34/p/3898569.html
http://blog.csdn.net/onion2007/article/details/46805335
时间： 2024-10-21 03:23:53