【原创】C语言读取BMP格式图片
【原创】C语言读取BMP格式图片
BMP是英文Bitmap（位图）的简写，它是Windows操作系统中的标准图像文件格式，能够被多种Windows应用程序所支持。随着Windows操作系统的流行与丰富的Windows应用程序的开发，BMP位图格式理所当然地被广泛应用。这种格式的特点是包含的图像信息较丰富，几乎不进行压缩，但由此导致了它与生俱生来的缺点--占用磁盘空间过大。所以，目前BMP在单机上比较流行。
BMP文件格式分析
简介
BMP(Bitmap-File)图形文件是Windows采用的图形文件格式，在Windows环境下运行的所有图象处理软件都支持BMP图象文件格式。Windows系统内部各图像绘制操作都是以BMP为基础的。Windows 3.0以前的BMP图文件格式与显示设备有关，因此把这种BMP图象文件格式称为设备相关位图DDB(device-dependent bitmap)文件格式。Windows 3.0以后的BMP图象文件与显示设备无关，因此把这种BMP图象文件格式称为设备无关位图DIB(device-independent bitmap)格式（注：Windows 3.0以后，在系统中仍然存在DDB位图，象BitBlt()这种函数就是基于DDB位图的，只不过如果你想将图像以BMP格式保存到磁盘文件中时，微软极力推荐你以DIB格式保存），目的是为了让Windows能够在任何类型的显示设备上显示所存储的图象。BMP位图文件默认的文件扩展名是BMP或者bmp（有时它也会以.DIB或.RLE作扩展名）。
位图文件结构表
位图文件 位图文件头 14 字节
位图信息头 40 字节
彩色表（调色板） 4N 字节
位图数据 x 字节
构件详解：
位图文件头
位图文件头包含文件类型、文件大小、存放位置等信息。结构定义如下：
typedef struct tagBITMAPFILEHEADER
{
UNIT bfType;
DWORD bfSize;
UINT bfReserved1;
UINT bfReserved2;
DWORD bfOffBits;
}BITMAPFILEHEADER;
其中：
bfType 说明文件类型，在windows系统中为BM。
bfSize 说明文件大小。
bfReserved1 bfReserved2 保留，设置为０。
bfOffBits 说明实际图形数据的偏移量。
位图信息头
位图信息头包含位图的大小、压缩类型、和颜色格式，结构定义如下：
typedef struct tagBITMAPINFOHEADER
{
DWORD biSize;
LONG biWidth;
LONG biHeight;
WORD biPlanes;
WORD biBitCount;
DWORD biCompression;
DWORD biSizeImage;
LONG biXPelsPerMerer;
LONG biYPelsPerMerer;
DWORD biClrUsed;
DWORD biClrImportant;
}BITMAPINFOHEADER;
其中：
biSize 说明BITMAPINFOHEADER结构所需字节数，在windows系统中为28h
biWidth 说明图像宽度
biHeight 说明图像高度
biPlanes 为目标设备说明位面数，其值设为１
biBitCount每个像素的位数，单色位图为１，２５６色为８，２４bit为２４。
biCompression压缩说明，BI_RGB：无压缩，BI_RLE8：８位RLE压缩，BI_RLE4：４位RLE压缩
biSizeImage说明图像大小，如无压缩，可设为０
biXPelsPerMeter水平分辨率
biYPelsPerMeter垂直分辨率
biClrUsed 位图使用的颜色数
biImportant重要颜色数目
彩色表
彩色表包含的元素与位图所具有的颜色数目相同，像素颜色用结构RGBQUAD来表示：
typedef struct tagRGBQUAD
{
BYTE rgbBlue;
BYTE rgbGreen;
BYTE rgbRed;
BYTE rgbReserved;
}RGBQUAD;
其中：
rgbBlue 指定蓝色强度
rgbGreen 指定绿色强度
rgbRed 指定红色强度
rgbReserved保留，设为０
位图数据
紧跟在彩色表后的是图像数据阵列，图像每一扫描行由连续的字节组成，扫描行由底向上存储，阵列中第一字节为左下角像素，最后一字节为右上角像素。
源代码1
/* File name: bmpTest.c
Description: Show all Info a bmp file has. including
FileHeader Info, InfoHeader Info and Data Part.
Reference: BMP图像数据的C语言读取源码
*/
#include "stdafx.h"
//#include
#include
#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);
/* Show bmp file tagBITMAPFILEHEADER info */
void bmpFileHeader(FILE* fpbmp);
/* Show bmp file tagBITMAPINFOHEADER info */
void bmpInfoHeader(FILE* fpbmp);
/* Show the Data Part of bmp file */
void bmpDataPart(FILE* fpbmp);
unsigned int OffSet = 0; // OffSet from Header part to Data Part
long BmpWidth = 0L; // The Width of the Data Part
long BmpHeight = 0L; // The Height of the Data Part
int main(int argc, char* argv[])
{
/* Open bmp file */
// FILE *fpbmp = fopen("lena.bmp", "r+");
FILE *fpbmp = fopen("picture.bmp", "r+");
if (fpbmp == NULL)
{
fprintf(stderr, "Open lena.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
bmpFileHeader(fpbmp); //Show the FileHeader Information
bmpInfoHeader(fpbmp); //Show the InfoHeader Information
bmpDataPart(fpbmp); //Reserve the data to file
fclose(fpbmp);
return 0;
}
/* Test the file is bmp file or not */
void bmpFileTest(FILE* fpbmp)
{
unsigned short bfType = 0;
fseek(fpbmp, 0L, SEEK_SET);
fread(&bfType, sizeof(char), 2, fpbmp);
if (BM != bfType)
{
fprintf(stderr, "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(&BmpWidth, sizeof(char), 4, fpbmp);
fread(&BmpHeight, sizeof(char), 4, fpbmp);
//printf("The Width of the bmp file is %ld.\n", BmpWidth);
//printf("The Height of the bmp file is %ld.\n", BmpHeight);
}
/* Show bmp file tagBITMAPFILEHEADER info */
void bmpFileHeader(FILE* fpbmp)
{
unsigned short bfType; //UNIT bfType;
unsigned int bfSize; //DWORD bfSize;
unsigned short bfReserved1; //UINT bfReserved1;
unsigned short bfReserved2; //UINT bfReserved2;
unsigned int bfOffBits; //DWORD bfOffBits;
fseek(fpbmp, 0L, SEEK_SET);
fread(&bfType, sizeof(char), 2, fpbmp);
fread(&bfSize, sizeof(char), 4, fpbmp);
fread(&bfReserved1, sizeof(char), 2, fpbmp);
fread(&bfReserved2, sizeof(char), 2, fpbmp);
fread(&bfOffBits, sizeof(char), 4, fpbmp);
printf("************************************************\n");
printf("*************tagBITMAPFILEHEADER info***********\n");
printf("************************************************\n");
printf("bfType is %d.\n", bfType);
printf("bfSize is %d.\n", bfSize);
printf("bfReserved1 is %d.\n", bfReserved1);
printf("bfReserved2 is %d.\n", bfReserved2);
printf("bfOffBits is %d.\n", bfOffBits);
}
/* Show bmp file tagBITMAPINFOHEADER info */
void bmpInfoHeader(FILE* fpbmp)
{
unsigned int biSize; // DWORD biSize;
long biWidth; // LONG biWidth;
long biHeight; // LONG biHeight;
unsigned int biPlanes; // WORD biPlanes;
unsigned int biBitCount; // WORD biBitCount;
unsigned int biCompression; // DWORD biCompression;
unsigned int biSizeImage; // DWORD biSizeImage;
long biXPelsPerMerer; // LONG biXPelsPerMerer;
long biYPelsPerMerer; // LONG biYPelsPerMerer;
unsigned int biClrUsed; // DWORD biClrUsed;
unsigned int biClrImportant; // DWORD biClrImportant;
fseek(fpbmp, 14L, SEEK_SET);
fread(&biSize, sizeof(char), 4, fpbmp);
fread(&biWidth, sizeof(char), 4, fpbmp);
fread(&biHeight, sizeof(char), 4, fpbmp);
fread(&biPlanes, sizeof(char), 4, fpbmp);
fread(&biBitCount, sizeof(char), 4, fpbmp);
fread(&biCompression, sizeof(char), 4, fpbmp);
fread(&biSizeImage, sizeof(char), 4, fpbmp);
fread(&biXPelsPerMerer, sizeof(char), 4, fpbmp);
fread(&biYPelsPerMerer, sizeof(char), 4, fpbmp);
fread(&biClrUsed, sizeof(char), 4, fpbmp);
fread(&biClrImportant, sizeof(char), 4, fpbmp);
printf("************************************************\n");
printf("*************tagBITMAPINFOHEADER info***********\n");
printf("************************************************\n");
printf("biSize is %d. \n", biSize);
printf("biWidth is %ld.\n", biWidth);
printf("biHeight is %ld.\n", biHeight);
printf("biPlanes is %d. \n", biPlanes);
printf("biBitCount is %d. \n", biBitCount);
printf("biCompression is %d. \n", biCompression);
printf("biSizeImage is %d. \n", biSizeImage);
printf("biXPelsPerMerer is %ld.\n", biXPelsPerMerer);
printf("biYPelsPerMerer is %ld.\n", biYPelsPerMerer);
printf("biClrUsed is %d. \n", biClrUsed);
printf("biClrImportant is %d. \n", biClrImportant);
}
/* Show the Data Part of bmp file */
void bmpDataPart(FILE* fpbmp)
{
int i, j;
// unsigned char bmpPixel[BmpWidth][BmpHeight];
unsigned char bmpPixel[1000][1000];
//因为暂时还未找到好的方法，暂且长和宽都设为1000，如果图像的尺寸大于1000，则要重新设置
unsigned char* bmpPixelTmp = NULL;
FILE* fpDataBmp;
/* New a file to save the data matrix */
if((fpDataBmp=fopen("bmpData.dat","w+")) == NULL)
{
fprintf(stderr, "Failed to construct file bmpData.dat.!!!");
exit(1);
}
fseek(fpbmp, OffSet, SEEK_SET);
if ((bmpPixelTmp=(unsigned char*)malloc(sizeof(char)*BmpWidth*BmpHeight))==NULL)
{
fprintf(stderr, "Data allocation failed.!!!\n");
exit(1);
}
fread(bmpPixelTmp, sizeof(char), BmpWidth*BmpHeight, fpbmp);
/* Read the data to Matrix and save it in file bmpData.dat */
for(i =0; i < BmpHeight; i++)
{
fprintf(fpDataBmp, "The data in line %-3d:\n", i+1);
for(j = 0; j < BmpWidth; j++)
{
bmpPixel[i][j] = bmpPixelTmp[BmpWidth*(BmpHeight-1-i)+j];
//fwrite(&chartmp, sizeof(char), 1, fpDataBmp);
fprintf(fpDataBmp, "%-3d ", bmpPixel[i][j]);
if ((j+1)%32 == 0)
{
fprintf(fpDataBmp, "\n");
}
}
}
/* Used to test the data read is true or false
You can open the file using Matlab to compare the data */
//printf("bmpPixel[2][3] is %d.\n", bmpPixel[2][3]);
//printf("bmpPixel[20][30] is %d.\n", bmpPixel[20][30]);
free(bmpPixelTmp);
fclose(fpDataBmp);
}
源代码2
// 读取图像2.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
//#include
#include
#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("lena.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=0;j