BMP格式图像读取与存储

全局变量:
 1 #include "stdafx.h"
 #include <windows.h>

 /*BMP位图数据是4字节对齐*/
 #define WIDTHBYTES(bits) ((DWORD)(((bits)+31) & (~31)) / 8)
 #define WIDTHBYTES(bits) ((DWORD)((((bits)+31) / 32) * 4)

 unsigned char *gPBmpBuf ;     //指向图像数据的指针
 int            gBmpWidth ;    //图像的宽
 int            gBmpHeight;     //图像的高
 RGBQUAD       *gPColorTable ; //颜色表指针
 int            gBiBitCount;   //图像类型，每个像素的位数
 char           bmp[] = "E:/test_pic.bmp";
 char           saveBmp[] = "E:/save_pic.bmp";

读取bmp文件：

 bool loadBmp(char *bmpName)
 {
     /*以二进制方式打开bmp文件*/
     FILE *fp = fopen(bmpName , "rb");
     if(NULL == fp)
     {
         printf("open file \"%s\" failed \n" , bmpName);
         return false ;
     }

     /*跳过bmp文件结构体*/
     fseek(fp , sizeof(BITMAPFILEHEADER),);

     /*读取bmp文件信息头*/
     BITMAPINFOHEADER infoHead ;
     fread(&infoHead , sizeof(BITMAPINFOHEADER), , fp);

     /*获取图像宽，高，像素位数*/
     gBmpWidth  = infoHead.biWidth ;
     gBmpHeight = infoHead.biHeight;
     gBiBitCount= infoHead.biBitCount;

     /*获取每行像素所占内存大小(必须为4的倍数)*/
     int lineByte = (gBmpWidth*gBiBitCount/ + )/* ;

     /*灰度图像有颜色表，且颜色表表项为256,24-位真彩色图像就不使用彩色板*/
     if( == gBiBitCount)
     {
         gPColorTable = (RGBQUAD *)malloc(sizeof(RGBQUAD)*);
         fread(gPColorTable , sizeof(RGBQUAD) ,   , fp);
     }

     /*申请位图数据空间，并将位图数据存放到内存*/
     gPBmpBuf = (unsigned char *)malloc(sizeof(unsigned char)*gBmpHeight*lineByte);
     fread(gPBmpBuf, ,gBmpHeight*lineByte,fp);

     fclose(fp);

     return true ;
 }

保存bmp文件格式：

 bool storeBmp(char *bmpName , unsigned char *imgBuf , int width , int height,
               int gBiBitCount , RGBQUAD *gPColorTable )
 {
     /*对位图数据进行判空操作*/
     if(NULL == imgBuf)
     {
         return false ;
     }

     /*根据像素位数，判断当前颜色表大小*/
     int colorTableSize =  ;
     if(gBiBitCount == )
     {
         /*
            1字节用于蓝色分量
            1字节用于绿色分量
            1字节用于红色分量
            1字节用于填充符(设置为0)
          */
         colorTableSize =  ; /*4*256*/
     }

     /*待存储图像数据每行像素的大小(4的倍数)*/
     int lineByte = (gBmpWidth*gBiBitCount/ + )/* ;

     FILE *fp = fopen(bmpName , "wb");
     if(NULL == fp)
     {
         printf("creat file failed !\n");
         return false ;
     }

     /*填写位图文件头结构体*/
     BITMAPFILEHEADER fileHead ;
     fileHead.bfType = 0x4D42 ; //bmp类型
     fileHead.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) +
                       colorTableSize + lineByte*height ;
     fileHead.bfReserved1 =  ;
     fileHead.bfReserved2 =  ;
     fileHead.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) +
                          colorTableSize ;
     fwrite(&fileHead , sizeof(BITMAPFILEHEADER), , fp);

     /*填写位图信息结构体*/
     BITMAPINFOHEADER infoHead ;
     infoHead.biBitCount = gBiBitCount ;
     infoHead.biClrImportant =  ;
     infoHead.biClrUsed =  ;
     infoHead.biCompression =  ;
     infoHead.biHeight = height ;
     infoHead.biPlanes =  ;
     infoHead.biSize =  ;
     infoHead.biSizeImage = lineByte*height ;
     infoHead.biWidth = width ;
     infoHead.biXPelsPerMeter =  ;
     infoHead.biYPelsPerMeter =  ;
     fwrite(&infoHead , sizeof(BITMAPINFOHEADER), , fp);

     /*填写颜色表*/
     if(gBiBitCount == )
     {
         fwrite(&gPColorTable , sizeof(RGBQUAD), , fp);
     }

      /*写位图数据进文件*/
     fwrite( imgBuf, height * lineByte, , fp );

     fclose(fp);

     return true ;
 }

main入口测试:

 int _tmain(int argc, _TCHAR* argv[])
 {

     bool ret = false ;

     ret |= loadBmp(bmp);
     ret |= storeBmp(saveBmp,gPBmpBuf,gBmpWidth,gBmpHeight,gBiBitCount,gPColorTable);

     if(false == ret)
     {
         printf("excut fail! \n");
     }
     else if(true == ret)
     {
         printf("excut success!\n");
     }

     if(gBiBitCount == )
     {
         free(gPColorTable);
     }

     free(gPBmpBuf);

     return ;
 }