【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



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