c语言实现24位彩色图像二值化

// huiduhua.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"#include<stdio.h>#include<windows.h>int _tmain(int argc, _TCHAR* argv[]){BITMAPFILEHEADER bfhead;BITMAPINFOHEADER bihead;RGBQUAD *pColorTable;unsigned char *pBmpBuf;FILE *fp1=fopen("鼠.bmp","rb");if(fp1==0)return 0;fread(&bfhead,14,1,fp1);   //将文件头读入内存fread(&bihead,40,1,fp1);   //将信息头读入内存int LineByte=(bihead.biWidth*24/8+3)/4*4; //保证每行字节数为4的整数倍pBmpBuf=new unsigned char[LineByte*bihead.biHeight]; //为数据区分配内存空间fread(pBmpBuf,LineByte*bihead.biHeight,1,fp1);       //将bmp数据区读入内存fclose(fp1); printf("Width:%d, Height: %d,biBitCount:%d\n",bihead.biWidth,bihead.biHeight,bihead.biBitCount);//现将真彩图灰度化int LineByte1=(bihead.biWidth*8/8+3)/4*4;  //由于灰度化后每像素位数变为8，所以每行字节数发生改变，但仍要求为4的整数倍FILE *fp2=fopen("鼠2.bmp","wb");if(fp2==0)return 0;//更改文件头，并将其保存bfhead.bfSize=14+40+sizeof(RGBQUAD)*256+LineByte1*bihead.biHeight;   //更改文件大小bfhead.bfOffBits=14+40+sizeof(RGBQUAD)*256;                          //更改偏移值fwrite(&bfhead,14,1,fp2); //更改信息头并将其保存bihead.biBitCount=8;    //更改每像素位数bihead.biSizeImage=LineByte1*bihead.biHeight;  //更改数据区大小fwrite(&bihead,40,1,fp2);//因为灰度化图像有颜色表，所以创建颜色表并保存pColorTable=new RGBQUAD[256];for(int i=0;i<256;i++)pColorTable[i].rgbRed = pColorTable[i].rgbGreen = pColorTable[i].rgbBlue = i;//使颜色表中每种颜色的R,G,B分量相等且等于索引值fwrite(pColorTable,sizeof(RGBQUAD),256,fp2);//改变数据区unsigned char *pBmpBuf1;pBmpBuf1=new unsigned char[LineByte1*bihead.biHeight];for(int i=0;i<bihead.biHeight;i++)for(int j=0;j<bihead.biWidth;j++){unsigned char *pb1,*pb2;pb1=pBmpBuf+i*LineByte+j*3;int y=*(pb1)*0.299+*(pb1+1)*0.587+*(pb1+2)*0.114;pb2=pBmpBuf1+i*LineByte1+j;*pb2=y;}//二值化方法一：阈值设为127，灰度值小于127的置零，其他的置为255；//for(int i=0;i<bihead.biHeight;i++)//for(int j=0;j<bihead.biWidth;j++)//{//unsigned char *pb;//pb=pBmpBuf1+i*LineByte1+j;//if(*pb<127)                 //将每个像素值与127比较//*pb=0;//else//*pb=255;//}//方法二:计算像素的平均值K，扫描图像的每个像素值如像素值大于K像素值设为255(白色)，值小于等于K像素值设为0(黑色)int y=0;//像素和int k=0;//像素个数for(int i=0;i<bihead.biHeight;i++)for(int j=0;j<bihead.biWidth;j++){unsigned char *pb;pb=pBmpBuf1+i*LineByte1+j;y=y+*pb;  //计算所有像素灰度值之和k++;      //统计像素个数}y=y/k; //求像素平均值for(int i=0;i<bihead.biHeight;i++)for(int j=0;j<bihead.biWidth;j++){unsigned char *pb1;pb1=pBmpBuf1+i*LineByte1+j;if(*pb1<y)         //将每个像素值与平均值作比较*pb1=0;else*pb1=255;}fwrite(pBmpBuf1,LineByte1*bihead.biHeight,1,fp2);fclose(fp2);system("pause");return 0;}