可以使用C语言标准函数库中的fopen、fseek、fclose等系列函数来打开bmp位图文件，以及进行相应的处理，下面是一个demo，仅供参考。以下代码在vc6.0中编译通过。
#include <stdio.h>#include <stdlib.h>
#define BITMAPFILEHEADERLENGTH 14 // The bmp FileHeader length is 14
#define BM 19778 // The ASCII code for BM
/* Test the file is bmp file or not */
void bmpFileTest(FILE* fpbmp)
/* To get the OffSet of header to data part */
void bmpHeaderPartLength(FILE* fpbmp)
/* To get the width and height of the bmp file */
void BmpWidthHeight(FILE* fpbmp)
//get r,g,b data
void bmpDataPart(FILE* fpbmp)
// output data to corresponding txt file
void bmpoutput(FILE *fpout)
unsigned int OffSet = 0 // OffSet from Header part to Data Part
long width // The Width of the Data Part
long height // The Height of the Data Part
unsigned char r[2000][2000],output_r[2000][2000]
unsigned char g[2000][2000],output_g[2000][2000]
unsigned char b[2000][2000],output_b[2000][2000]
int main(int argc, char* argv[])
{
/* Open bmp file */
unsigned char *fp_temp
FILE *fpbmp
FILE *fpout
fpbmp= fopen("1.bmp", "rb")
if (fpbmp == NULL)
{
printf("Open bmp failed!!!\n")
return 1
}
fpout= fopen("out.bmp", "wb+")
if (fpout == NULL)
{
printf("Open out.bmp failed!!!\n")
return 1
}
bmpFileTest(fpbmp) //Test the file is bmp file or not
bmpHeaderPartLength(fpbmp) //Get the length of Header Part
BmpWidthHeight(fpbmp) //Get the width and width of the Data Part
//
fseek(fpbmp, 0L, SEEK_SET)
fseek(fpout, 0L, SEEK_SET)
fp_temp=(unsigned char *)malloc(OffSet)
fread(fp_temp, 1, OffSet, fpbmp)
fwrite(fp_temp,1,OffSet,fpout)
bmpDataPart(fpbmp) //Reserve the data to file
/*
如果您想对图片进行处理，请您再这里插入处理函数!!!!!!!!!!!!!!!!!!
*/
bmpoutput(fpout)
fclose(fpbmp)
fclose(fpout)
return 0
}
void bmpoutput(FILE* fpout)
{
int i, j=0
int stride
unsigned char* pixout=NULL
stride=(24*width+31)/8
stride=stride/4*4
pixout=(unsigned char *)malloc(stride)
fseek(fpout, OffSet, SEEK_SET)
for(j=0j<heightj++)
{
for(i=0i<widthi++)
{
pixout[i*3+2]=output_r[height-1-j][i]
pixout[i*3+1]=output_g[height-1-j][i]
pixout[i*3] =output_b[height-1-j][i]
}
fwrite(pixout, 1, stride, fpout)
}
}
void bmpDataPart(FILE* fpbmp)
{
int i, j=0
int stride
unsigned char* pix=NULL
FILE* fpr
FILE* fpg
FILE* fpb
if((fpr=fopen("bmpr.txt","w+")) == NULL)
{
printf("Failed to construct file bmpr.txt.!!!")
exit(1)
}
if((fpg=fopen("bmpg.txt","w+")) == NULL)
{
printf("Failed to construct file bmpg.txt.!!!")
exit(1)
}
if((fpb=fopen("bmpb.txt","w+")) == NULL)
{
printf("Failed to construct file bmpb.txt.!!!")
exit(1)
}
fseek(fpbmp, OffSet, SEEK_SET)
stride=(24*width+31)/8
stride=stride/4*4
pix=(unsigned char *)malloc(stride)
for(j=0j<heightj++)
{
fread(pix, 1, stride, fpbmp)
for(i=0i<widthi++)
{
r[height-1-j][i] =pix[i*3+2]
g[height-1-j][i] =pix[i*3+1]
b[height-1-j][i] =pix[i*3]
output_r[height-1-j][i] =pix[i*3+2]
output_g[height-1-j][i] =pix[i*3+1]
output_b[height-1-j][i] =pix[i*3]
}
}
for(i =0 i < height i++)
{
for(j = 0 j < width-1 j++)
{
fprintf(fpb,"%4d",b[i][j])
fprintf(fpg,"%4d",g[i][j])
fprintf(fpr,"%4d",r[i][j])
}
fprintf(fpb,"%4d\n",b[i][j])
fprintf(fpg,"%4d\n",g[i][j])
fprintf(fpr,"%4d\n",r[i][j])
}
fclose(fpr)
fclose(fpg)
fclose(fpb)
}
void bmpFileTest(FILE* fpbmp)
{
unsigned short bfType = 0
fseek(fpbmp, 0L, SEEK_SET)//seek_set 起始位置
fread(&bfType, sizeof(char), 2, fpbmp)
if (BM != bfType)
{
printf("This file is not bmp file.!!!\n")
exit(1)
}
}
/* To get the OffSet of header to data part */
void bmpHeaderPartLength(FILE* fpbmp)
{
fseek(fpbmp, 10L, SEEK_SET)
fread(&OffSet, sizeof(char), 4, fpbmp)
printf("The Header Part is of length %d.\n", OffSet)
}
/* To get the width and height of the bmp file */
void BmpWidthHeight(FILE* fpbmp)
{
fseek(fpbmp, 18L, SEEK_SET)
fread(&width, sizeof(char), 4, fpbmp)
fseek(fpbmp, 22L, SEEK_SET)
fread(&height, sizeof(char), 4, fpbmp)
printf("The Width of the bmp file is %ld.\n", width)
printf("The Height of the bmp file is %ld.\n", height)
}
