如何依次读出位深为24的BMP图像的RGB值？ 用VC。32位呢？

[huguangdieying]

如题.最好给一小段程序。

[pathuang68]

网上搜搜应该有很多的。
我本来要写一片类似的博文的，里面画了一些图，解释得应该比较清楚，可惜这几天根本没有办法发待图片的博文...
CSDN咋就这么...

[ltc_mouse]

BMP文件的格式不复杂。网络上有很多现成的，google下吧~~

[lingyin55]

参考
http://topic.csdn.net/t/20060415/22/4689702.html

[blingpro]

定义BMP位图结构

#pragma pack(1)
typedef struct tagBITMAPFILEHEADER
{
	char bfType[2]; // 位图文件的类型，必须为BM
	unsigned long int bfSize; // 位图文件的大小，以字节为单位
	unsigned short bfReserved1; // 位图文件保留字，必须为0
	unsigned short bfReserved2;
	unsigned long int bfOffBits; // 位图数据的起始位置，以相对于位图// 文件头的偏移量表示，以字节为单位
} BITMAPFILEHEADER;


typedef struct tagBITMAPINFOHEADER
{
	unsigned long int biSize;
	unsigned long int biWidth;
	unsigned long int biHeight;
	unsigned short int biPlanes; 
	unsigned short int biBitCount;
	unsigned long int biCompression;
	unsigned long int biSizelmage;
	unsigned long int biXPelsPerMeter;
	unsigned long int biYPelsPerMeter;
	unsigned long int biClrUsed;
	unsigned long int biClrlmportant;

}BITMAPINFOHEADER;

typedef  struct tagRGBQUAD
{
	unsigned char rgbBlue;
	unsigned char rgbGreen;
	unsigned char rgbRed; 
	unsigned char rgbReserved;

}RGBQUAD;


typedef struct tagBITMAPINFO
{
	BITMAPINFOHEADER bmiHeader;
	RGBQUAD bmiColor[1];

}BITMAPINFO;


typedef struct tagBMP
{
	BITMAPFILEHEADER bmpFileHeader;
	BITMAPINFO bmpInfo;
}BMP;

#pragma pack()

读取文件头结构

void CBmpData::storeHeadFromFile(string strFileName)
{

	ifstream in;
	locale::global(locale(""));
	in.open(strFileName.c_str(),ios_base::binary);
	if(!in)
	{
		cout<<"打开文件失败"<<endl;
		return;
	}
	locale::global(locale("C"));

	BMP *bmp = new BMP;
	
	in.read(bmp->bmpFileHeader.bfType,2);
	in.read((char*)&(bmp->bmpFileHeader.bfSize),4);
	in.read((char*)&(bmp->bmpFileHeader.bfReserved1),2);
	in.read((char*)&(bmp->bmpFileHeader.bfReserved2),2);
	in.read((char*)&(bmp->bmpFileHeader.bfOffBits),4);

	in.read((char*)&(bmp->bmpInfo.bmiHeader.biSize),4);
	in.read((char*)&(bmp->bmpInfo.bmiHeader.biWidth),4);
	in.read((char*)&(bmp->bmpInfo.bmiHeader.biHeight),4);
	in.read((char*)&(bmp->bmpInfo.bmiHeader.biPlanes),2);
	in.read((char*)&(bmp->bmpInfo.bmiHeader.biBitCount),2);
	in.read((char*)&(bmp->bmpInfo.bmiHeader.biCompression),4);
	in.read((char*)&(bmp->bmpInfo.bmiHeader.biSizelmage),4);
	in.read((char*)&(bmp->bmpInfo.bmiHeader.biXPelsPerMeter),4);
	in.read((char*)&(bmp->bmpInfo.bmiHeader.biYPelsPerMeter),4);
	in.read((char*)&(bmp->bmpInfo.bmiHeader.biClrUsed),4);
	in.read((char*)&(bmp->bmpInfo.bmiHeader.biClrlmportant),4);

	if(bmp->bmpInfo.bmiHeader.biBitCount != 24)
	{
		in.read((char*)&(bmp->bmpInfo.bmiColor[0].rgbBlue),1);
		in.read((char*)&(bmp->bmpInfo.bmiColor[0].rgbGreen),1);
		in.read((char*)&(bmp->bmpInfo.bmiColor[0].rgbRed),1);
		in.read((char*)&(bmp->bmpInfo.bmiColor[0].rgbReserved),1);
	}

	mHead = (void*)bmp;
	mHeadLength = bmp->bmpFileHeader.bfOffBits;
	width = bmp->bmpInfo.bmiHeader.biWidth;
	height = bmp->bmpInfo.bmiHeader.biHeight;

	in.close();

}

//偏移一下文件头的位置，然后读入数据

in.seekg(mHeadLength);          //偏移

	mRed = new int*[height];
	mGreen = new int*[height];
	mBlue = new int*[height];

	for(int i = 0;i<height;i++)
	{
		mRed[i] = new int[width];
		mGreen[i] = new int[width];
		mBlue[i] = new int[width];
	}

	for(int i = height-1;i>=0;i--)
	{
		for(int j = 0;j<width;j++)
		{
			unsigned char ci[3];
			in.read((char*)&ci,3); 

			mRed[i][j] = (int)ci[2];
			mGreen[i][j] = (int)ci[1];
			mBlue[i][j] = (int)ci[0];
		}
	}

供参考，gl

[青葱岁月不可追]

图片有具体的格式的，hoho

以前截取过24位图的信息，找找代码啊！~

[青葱岁月不可追]

/**
* @file      21.c
* @author    hoho
* @brief
* This file is used for getting the transversal picture on principle in the form of BMP.
*/

#include <stdio.h>
#include <stdlib.h>

typedef  unsigned char BYTE;
typedef  unsigned short int WORD;
typedef  unsigned long int DWORD;

#pragma pack (2) 
struct SBmpHeader
{
    WORD 	bfType;
	DWORD 	bfSize;
	WORD 	bfReserved1;
	WORD 	bfReserved2;
	DWORD 	bfOffBits;
	DWORD	biSize;
 	DWORD   biWidth;
    DWORD   biHeight;
    WORD    biPlanes;
    WORD    biBitCount;
    DWORD   biComperssion;
    DWORD   biSizeImage; 
    DWORD   biXPelsPerMeter;
    DWORD   biYPelsPerMeter;
    DWORD   biClrUsed;
    DWORD   biClrImportant;
}SSourceHeader,SDestHeader;
#pragma pack ()

/** 
* @brief
*The function named judge_getborder is used for judging the area of number from command.
*If the area is beyond the mark,it will show an information and exit the program.
* @param argv0        the point of one of the start coordinate.
* @param argv1        the point of the width or height which needed.
* @param border       the border of the picture.
*/
void judge_getborder(char *argv0,char *argv1,WORD border)  
{
    if((atoi(argv0) + atoi(argv1)) > border)
    {
        printf("The data you wanted is beyond the mark.\n");
        exit(0);
    }    
}
      
/** 
* @brief
*The function named judge_number is used for judging the validity of number from command.
*If the data is not numbers,it will show an information and exit the program.
* @param argv        the point of the parameter.
*/
void judge_number(char *argv,WORD measure) 
{
    int i;
    
    for(i = 0;i < strlen(argv);)
    {
        if((argv[i] >= 48) && (argv[i] <= 57))
        {
            i++;
        }
        else
        {	
            printf("The x-axis y-axis width height must be the number between 0 and 9.\n");
        	exit(0);   
        }        
    }
    if((atoi(argv) < 0) || (atoi(argv) > measure))
    {
        printf("The data must between 0 and %d.\n",measure);
    	exit(0);    
    }             
}

/** 
* @brief
*The function named judge_validity is used for judging the validity of number from command.
*Call the judge_number and judge_getborder functions to judge.
*If the number is of no effect,it will show an information and exit the program.
* @param argv4        the point of the forth parameter(the x-axis of the start point).
* @param argv5        the point of the fifth parameter(the y-axis of the start point).
* @param argv6        the point of the sixth parameter(the width of the destination).
* @param argv7        the point of the seventh parameter(the height of the destination).
* @param width        the width of the source picture.
* @param height       the height of the source picture.
*/
void judge_validity(char *argv4,char *argv5,char *argv6,char *argv7,unsigned long int width,unsigned long int height)
{
    judge_number(argv4,width);
    judge_number(argv5,height);
    judge_number(argv6,width);
    judge_number(argv7,height);
    judge_getborder(argv4,argv6,width);
    judge_getborder(argv5,argv7,height);
}    

/** 
* @brief
*The function named trans_bmp is used for getting the transversal picture on principle in the form of BMP.
*First,read the data of BMP.
*Second,call the function named judge_validity to judging the validity of number from command.
*Then,getting the transerval picture.
* @param argv2        the point of the second parameter(the source picture).
* @param argv3        the point of the third parameter(the destination picture).
* @param argv4        the point of the forth parameter(the x-axis of the start point).
* @param argv5        the point of the fifth parameter(the y-axis of the start point).
* @param argv6        the point of the sixth parameter(the width of the destination).
* @param argv7        the point of the seventh parameter(the height of the destination).
*/
void trans_bmp(char *argv2,char *argv3,char *argv4,char *argv5,char *argv6,char *argv7) 
{
    FILE *fps,*fpd;
    BYTE *sbmpdata,*dbmpdata;
    DWORD i,j,count,SourceDataPerLine,DestDataPerLine;
    int x,y,width,height;
    
    //if(((fps = fopen(argv2,"rb")) == NULL) || ((fpd = fopen(argv3,"wb")) == NULL))
    if((fps = fopen(argv2,"rb")) == NULL) 
    {
        printf("Can't open the file.\n");
        exit(0);
    }

    fread(&SSourceHeader,sizeof(struct SBmpHeader),1,fps);
    
 	if((SSourceHeader.bfType != 0x4d42) || (SSourceHeader.biBitCount != 0x18))
 	{
 	    printf("Error!The type of picture must be 24-Bitmap-File!\n");
 	    exit(0);
 	}
	
 	judge_validity(argv4,argv5,argv6,argv7,SSourceHeader.biWidth,SSourceHeader.biHeight);
 	
   	if((fpd = fopen(argv3,"wb")) == NULL)
   	{
        printf("Can't open the file.\n");
        exit(0);
   	}  

    /*
 	fseek(fps,0,SEEK_SET);
 	fread(&SDestHeader,sizeof(struct SBmpHeader),1,fps);
 	fseek(fps,SSourceHeader.bfOffBits,SEEK_SET);
 	*/
  	SDestHeader = SSourceHeader; 
         
	x = atoi(argv4);
 	y = atoi(argv5);
 	width = atoi(argv6);
 	height = atoi(argv7);	
  	SourceDataPerLine = (SSourceHeader.biWidth * SSourceHeader.biBitCount + 31) / 32 * 4;
  	DestDataPerLine = (width * SDestHeader.biBitCount + 31) / 32 * 4;

    sbmpdata = (BYTE *)malloc(SourceDataPerLine * SSourceHeader.biHeight);
    dbmpdata = (BYTE *)malloc(DestDataPerLine * height);
 	
    fread(sbmpdata,(SourceDataPerLine * SSourceHeader.biHeight),1,fps);      	
 	
	count = 0;
	for(i = 0;i < height;i++)
    {
        for(j = 0;j < DestDataPerLine;j++)
    	{
         	//dbmpdata[count] = sbmpdata[(y + i) * SourceDataPerLine + x * 3 + j]; //get the picture from the default starting point(bottom left corner).
          	dbmpdata[count] = sbmpdata[(SSourceHeader.biHeight - y - height + i) * SourceDataPerLine + x * 3 + j]; //get the picture from the conceived starting point(top left corner).    
        	count++;        
		}
	}
  
	SDestHeader.biWidth = width;
 	SDestHeader.biHeight = height;
 	SDestHeader.biSizeImage = (height * DestDataPerLine);
 	SDestHeader.bfSize = sizeof(struct SBmpHeader) + SDestHeader.biSizeImage;

 	fwrite(&SDestHeader,sizeof(struct SBmpHeader),1,fpd); 
 	fwrite(dbmpdata,sizeof(BYTE),SDestHeader.biSizeImage,fpd); 
	fclose(fpd);
 	fclose(fps); 	            
}

/** 
* @brief
*The function named judge_paramnum is used for judging the number of parameter.
*If the number is less than 7,it will give an information and exit the programme.
* @param argc         the number of parameters.
*/
void judge_paramnum(int argc)
{
    if(argc < 7)
    {
        printf("Input Error!Usage:source.bmp des.bmp x-axis y-axis width height\n");
        exit(0); 
    }           
} 

int main(int argc, char *argv[])
{
    judge_paramnum(argc);
    trans_bmp(argv[1],argv[2],argv[3],argv[4],argv[5],argv[6]);
    return 0;
}

[青葱岁月不可追]

楼主凑乎着看吧！~hoho一个截图的程序

ps：斑竹们，我错了，不应该直接给代码的……不过我贴的代码里只有一部分是楼主需要的！~

[「已注销」]

bool zzTexture::LoadImage( CString & path )
{
    FILE *file = NULL;

    int cx,cy, panels, bitcount;

    file = _tfopen( path, _T("rb") );
    
    if ( file == NULL )
    {
        return false;
    }

    fseek(file, 18, SEEK_CUR);

    // width
    {
        int c, c1, c2, c3;
        c    = getc( file );
        c1   = getc( file );
        c2   = getc( file );
        c3   = getc( file );

        cx = ((unsigned int) c) + (((unsigned int) c1) << 8) + 
            (((unsigned int) c2) << 16) + (((unsigned int) c3) << 24);

    }

    // height
    {
        int c, c1, c2, c3;
        c    = getc( file );
        c1   = getc( file );
        c2   = getc( file );
        c3   = getc( file );

        cy = ((unsigned int) c) + (((unsigned int) c1) << 8) + 
            (((unsigned int) c2) << 16) + (((unsigned int) c3) << 24);

    }

    // panels
    {
        int c, c1;

        c = getc(file);  
        c1 = getc(file);

        panels =  ((unsigned int) c) + (((unsigned int) c1) << 8) ;

    }

    // bit counts
    {
        int c, c1;

        c = getc(file);  
        c1 = getc(file);

        bitcount =  ((unsigned int) c) + (((unsigned int) c1) << 8) ;

    }

    fseek(file, 24, SEEK_CUR);

    int size = cx * cy * bitcount / 8;

    byte *lpBits = new byte[size];

    fread( lpBits, size, 1, file );

    // lpBits 指针 指向RGB值 信息 袄 不对应该是BGR格式读进来的你可以自己做个循环调换
    glGenTextures(1, &m_ID);

     GLboolean o = glIsTexture(
         m_ID
        );

    glBindTexture( GL_TEXTURE_2D, m_ID);
    glTexImage2D(  GL_TEXTURE_2D, 
        0, 
        3, 
        cx, 
        cy, 
        0, 
        GL_RGB, 
        GL_UNSIGNED_BYTE, 
        lpBits);


    delete [] lpBits;
    return true;
}

过去自己写的一段代码给你参考哈

[huguangdieying]

FILE *fp;
LONG i,j,MapHeight,MapWidth,DataSizePerLine,DataSizePerLine1;

BITMAPINFOHEADER infoheader;
memset(&infoheader,0,sizeof(BITMAPINFOHEADER));


fp=fopen(fileName,"rb");


fseek(fp,14,SEEK_SET); //指针移动
fread(&infoheader,sizeof(BITMAPINFOHEADER),1,fp); //infoheader指向信息头
MapHeight=infoheader.biHeight;
MapWidth=infoheader.biWidth;



if(infoheader.biBitCount==24)
{
DataSizePerLine= (MapWidth* infoheader.biBitCount+31)/8; // 一个扫描行所占的字节数
DataSizePerLine= DataSizePerLine/4*4; // 字节数必须是4的倍数 每个扫描行所占的字节数

DataSizePerLine1=MapWidth* infoheader.biBitCount/8;


for(i=0;i<MapHeight;i++)
{
for(j=0;j<MapWidth;j++)
{
int b1,g1,r1;
b1=fgetc(fp);
g1=fgetc(fp);
r1=fgetc(fp);
}
if(DataSizePerLine1!=DataSizePerLine)
{for(long i=DataSizePerLine;i>DataSizePerLine1;i--) fgetc(fp);
}
}
} //if


fclose(fp);

并没有实现什么功能。各位帮忙看一下，这样读24位的BMP文件每个像素的RGB值对不对？

[pathuang68]

参考这个：例解BITMAP的数据格式