如何读入位图（二）

如何读入位图（二）

(2009-03-25 21:25:16)

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标签： 杂谈

分类： 数字图像处理

在C语言中没有预定义WORD和DWORD的数据类型，因此我们可以和它们同样字节的数据类型来代替，如下：

typedef unsigned short WORD;

typedef unsigned long DWORD;

typedef long LONG;

typedef unsigned char BYTE;

//文件头结构体

typedef struct tagBITMAPFILEHEADER

{ // bmfh

    WORD    bfType;

    DWORD   bfSize;

    WORD    bfReserved1;

    WORD    bfReserved2;

    DWORD   bfOffBits;

}BITMAPFILEHEADER;

//信息头结构体

typedef struct tagBITMAPINFOHEADER

{ // bmih

    DWORD biSize;

    LONG   biWidth;

    LONG   biHeight;

    WORD   biPlanes;

    WORD   biBitCount;

    DWORD biCompression;

    DWORD biSizeImage;

    LONG   biXPelsPerMeter;

    LONG   biYPelsPerMeter;

    DWORD biClrUsed;

    DWORD biClrImportant;

}BITMAPINFOHEADER;

//调色板项结构体

typedef struct tagRGBQUAD

{ // rgbq

    BYTE    rgbBlue;

    BYTE    rgbGreen;

    BYTE    rgbRed;

    BYTE    rgbReserved;

}RGBQUAD;

 

用C语言读入文件头：

int ReadFileHeader(char *filepath,BITMAPFILEHEADER *bmfh)

{

       FILE *fp;

       //打开文件

       fp=fopen(filepath,"rb");

       if(!fp)

       {     //如果打开失败

              printf("Can not open the file:%s\n",filepath);

              return -1;

       }

       //读入bfType

       if(fread(&bmfh->bfType,sizeof(WORD),1,fp)!=1)

       {

              printf("Can not read bfType in the file header.\n");

              fclose(fp);

              return -1;

       }

       //读入bfSize

       if(fread(&bmfh->bfSize,sizeof(DWORD),1,fp)!=1)

       {

              printf("Can not read bfSize in the file header.\n");

              fclose(fp);

              return -1;

       }

       //读入bfReserved1

       if(fread(&bmfh->bfReserved1,sizeof(WORD),1,fp)!=1)

       {

              printf("Can not read bfReserved1 in the file header.\n");

              fclose(fp);

              return -1;

       }

       //读入bfReserved2

       if(fread(&bmfh->bfReserved2,sizeof(WORD),1,fp)!=1)

       {

              printf("Can not read bfReserved2 in the file header.\n");

              fclose(fp);

              return -1;

       }

       //读入bfOffBits

       if(fread(&bmfh->bfOffBits,sizeof(DWORD),1,fp)!=1)

       {

              printf("Can not read bfOffBits in the file header.\n");

              fclose(fp);

              return -1;

       }

       //关闭文件指针

       fclose(fp);

       return 0;

}