自从上一次写了，后来是准备马上就写程序了，谁知后来就忘了，昨天突然想起来就将其写了出来。

　　程序的功能是将彩色图转灰度图，中间彩色和灰度的文件header都用到了，程序的流程我想我写的还是比较清楚的。没有用到Windows下的某些函数,在Linux下应该也能运行。

#include 
     
      #include 
      
       using namespace std;#pragma pack(2)        //两字节对齐，否则bmp_fileheader会占16Bytestruct bmp_fileheader{    unsigned short    bfType;        //若不对齐，这个会占4Byte    unsigned long    bfSize;    unsigned short    bfReverved1;    unsigned short    bfReverved2;    unsigned long    bfOffBits;};struct bmp_infoheader{    unsigned long    biSize;    unsigned long    biWidth;    unsigned long    biHeight;    unsigned short    biPlanes;    unsigned short    biBitCount;    unsigned long    biCompression;    unsigned long    biSizeImage;    unsigned long    biXPelsPerMeter;    unsigned long    biYpelsPerMeter;    unsigned long    biClrUsed;    unsigned long    biClrImportant;};fstream input_file;fstream output_file;struct bmp_fileheader bfh;struct bmp_infoheader bih;unsigned char *src_buff;unsigned char *dst_buff;void read_bmp_fileheader(){    input_file.read((char*)&bfh,sizeof(struct bmp_fileheader));}void read_bmp_infoheader(){    input_file.read((char*)&bih,sizeof(struct bmp_infoheader));}void read_bmp_data(){    src_buff=new unsigned char[bih.biHeight*bih.biWidth*3];    input_file.read((char*)src_buff,sizeof(unsigned char)*bih.biHeight*bih.biWidth*3);    }void bmp_rgb2gray(){    dst_buff=new unsigned char[bih.biHeight*bih.biWidth];    int tmp;    unsigned long j=0;    for (unsigned long i=0;i