C语言完成二值图像模拟灰值图像显示效果

M3(8×8阵)比较特殊，称为Bayer抖动表。M4是一个16×16的矩阵。
 
M3 表模拟灰值图像显示效果：
 
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#pragma pack(1)   //全紧凑模式
 
typedef struct {
 unsigned char bfType[2];
 unsigned long bfSize;
 unsigned short bfReserved1;
 unsigned short bfReserved2;
 unsigned long bfOffBits;
}bitmapFileHeader;
 
typedef struct {
 unsigned long biSize;
 unsigned long biWidth;
 unsigned long biHeight;
 unsigned short biPlanes;
 unsigned short biBitCount;
 unsigned long biCompression;
 unsigned long biSizeImage;
 long biXPixPerMeter;
 long biYPixPerMeter;
 unsigned long biClrUsed;
 unsigned long biClrImportant;
}bitmapInfoHeader;
 
 
typedef struct{
 unsigned char rgbBlue;
 unsigned char rgbGreen;
 unsigned char rgbRed;
 unsigned char rgbReserved;
 
}rgbQUAD;
 
typedef struct{
 bitmapFileHeader bfHeader;
 bitmapInfoHeader biHeader;
 rgbQUAD palette[256];
 unsigned char *imgData;
}bmp;
 
int main(){
 FILE *fp;
 if((fp=fopen("d:\Temp\\test_gray.bmp","rb"))==NULL){
  perror("can not open file!");
  return -1;
 }
 //读入彩色bmp图像文件头，信息头和图像数据
 bitmapFileHeader bfHeader;
 fread(&bfHeader,14,1,fp);
 bitmapInfoHeader biHeader;
 fread(&biHeader,40,1,fp);
 int imSize=biHeader.biSizeImage;
 int width=biHeader.biWidth;
 int height=biHeader.biHeight;
 int bitCount=biHeader.biBitCount;
 int lineBytes=(width*bitCount+31)/32*4;
 
 fseek(fp,bfHeader.bfOffBits,SEEK_SET);
 unsigned char*imageData=(unsigned char*)malloc(imSize*sizeof(unsigned char));
 fread(imageData,imSize*sizeof(unsigned char),1,fp);
 fclose(fp);
 
 bmp b;
 memcpy(&(b.bfHeader),&bfHeader,sizeof(bfHeader));
 memcpy(&(b.biHeader),&biHeader,sizeof(biHeader));
 b.imgData=(unsigned char*)malloc(sizeof(unsigned char)*imSize);
 memset(b.imgData,0,sizeof(unsigned char)*imSize);
 for(int i=0;i<256;i++){
  b.palette[i].rgbBlue=i;
  b.palette[i].rgbGreen=i;
  b.palette[i].rgbRed=i;
 }
 
 int i,j,temp;
 unsigned char bayer[8][8]={  
  0,32,8,40,2,34,10,42,
  48,16,56,24,50,18,58,26,
  12,44,4,36,14,46,6,38,
  60,28,52,20,62,30,54,22,
  3,35,11,43,1,33,9,41,
        51,19,59,27,49,17,57,25,
  15,47,7,39,13,45,5,37,
        63,31,55,23,61,29,53,21
 };
 for(i=0;i<height;i++){
  for(j=0;j<width;j++){
   temp=imageData[lineBytes*i+j];
   if((temp>>2)>bayer[i&7][j&7])
    b.imgData[lineBytes*i+j]=255;
   else
    b.imgData[lineBytes*i+j]=0;
  }
 }