图像RGB格式与YUV格式互转

 // rgb2yuv.cpp : 定义控制台应用程序的入口点。
 //

 #include "stdafx.h"

 #define Level 256   //直方图bin数
 #define SIZEX 176   //image列尺寸
 #define SIZEY 256   //image列尺寸
 #define READ 0
 #define WRITE 1

 unsigned char image_in[SIZEY*SIZEX*];
 unsigned char image_out[SIZEY*SIZEX*];
 float Y[SIZEX*SIZEY], U[SIZEX*SIZEY], V[SIZEX*SIZEY];
 float Y_out[SIZEX*SIZEY];

 void GetFileName(char *name , char *message)
 {
     if((NULL == name) || (NULL == message))
     {
         return ;
     }

     printf("%s" , message);
     scanf("%s" , name);
 }

 FILE * FileOpen(char *fileName , int mode)
 {
     FILE *filePoint ;
     char *option = "" ;

     if(mode == READ)
     {
         option = "r+b";
     }
     else if(mode == WRITE)
     {
         option = "w+b";
     }

     if(NULL == (filePoint = fopen(fileName , option)))
     {
         printf("File Open Fail!\n");
     }

     return filePoint ;
 }

 void ReadImageData(FILE *filePoint)
 {
     if(filePoint == NULL)
     {
         return ;
     }

     int y_count ;
     unsigned char temp =  ;

     for(y_count =  ; y_count < SIZEX*SIZEY ; y_count++)
     {
         fscanf(filePoint , "%c" , &temp);
         image_in[y_count] = temp ;
     }
 }

 void Histogram(long *hist)
 {
     int i , num ;

     for(num =  ; num < Level ; num++)
     {
         hist[num] =  ;
     }

     for(i =  ; i < SIZEX*SIZEY ; i++)
     {
         num = Y[i];
         hist[num]++;
     }

     for(num =  ; num < Level ; num++)
     {
         printf("%d \n" , hist[num]);
     }
 }

 void Equalization(long *hist ,long *q)
 {
     int i,n;
     long sum=;

     for(i=;i<;i++)
     {
         sum += hist[i];   /* find distribution */
         q[i]=(int) (sum*Level/((float)SIZEY*SIZEX));
     }
 }

 void Calculate(long *q)
 {
      int i, y, data;

       for(i=;i<SIZEX*SIZEY;i++){
             data = Y[SIZEX*SIZEY];
             Y_out[SIZEX*SIZEY] = q[data];
          }
 }

 void WriteImageData(FILE *file_p)
 {
     int Y_Count;

     for(Y_Count = ; Y_Count < SIZEX*SIZEY*; Y_Count++)
     {
              fprintf(file_p, "%c", image_out[Y_Count]);
     }
 }

 int _tmain(int argc, _TCHAR* argv[])
 {
     FILE *in , *out;

     char source[],destin[];
     char *message1="Input  Data File Name : " ;
     char *message2="Output Data File Name : " ;

     int i ;
     long hist[Level] = {} ;
     long q[Level]    = {} ;
     unsigned char Red[SIZEX*SIZEY] = {} ;
     unsigned char Green[SIZEX*SIZEY] = {} ;
     unsigned char Blue[SIZEX*SIZEY] = {} ;

     /*读取源文件名*/
     GetFileName(source , message1);
     GetFileName(destin , message2);

     /*打开源文件/目的文件*/
     in  = FileOpen(source , READ);
     out = FileOpen(destin , WRITE);

     /*读取源文件数据*/
     ReadImageData(in);

     /*RGB2YUV*/
     for(i =  ; i < SIZEX*SIZEY; i++)
     {
         /*Get RGB Data*/
         Red[i]   = image_in[i*] ;
         Green[i] = image_in[i*+] ;
         Blue[i]  = image_in[i*+] ; 

         /*RGB to YUV*/
         Y[i] = 0.3*Red[i] + 0.59*Green[i] + 0.11*Blue[i] ;
         U[i] = (Blue[i]-Y[i]) * 0.493;
         V[i] = (Red[i]-Y[i]) * 0.877;
     }

     /*直方图信息统计*/
     Histogram(hist);

     /*直方图均衡*/
     Equalization(hist , q);

     /*直方图计算*/
     Calculate(q); 

     for(i=; i < SIZEX*SIZEY; i++)
     {
         Red[i] = Y_out[i] + 0.956*U[i] + 0.621*V[i];
         Green[i] = Y_out[i] + 0.272*U[i] + 0.647*V[i];
         Blue[i] = Y_out[i] + 1.1061*U[i] + 1.703*V[i];
     }

     for(i=; i < SIZEY*SIZEX; i++)
     {   

         image_out[i*] = Red[i];
         image_out[i*+] = Green[i];
         image_out[i*+] = Blue[i];
     }

     WriteImageData(out);
     fcloseall();

     return ;
 }

示例图片：

sample.jpg:                     UV分量：