C語(yǔ)言實(shí)現(xiàn)二值圖像模擬灰值圖像顯示效果

更新時(shí)間：2021年10月25日 14:32:41 作者：混z

這篇文章主要為大家詳細(xì)介紹了C語(yǔ)言實(shí)現(xiàn)二值圖像模擬灰值圖像顯示效果，分為圖案法、抖動(dòng)法兩個(gè)方法實(shí)現(xiàn)，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

本文實(shí)例為大家分享了C語(yǔ)言實(shí)現(xiàn)二值圖像模擬灰值圖像顯示效果的具體代碼，供大家參考，具體內(nèi)容如下

圖案法

圖案法(patterning)是指灰度可以用一定比例的黑白點(diǎn)組成的區(qū)域表示，從而達(dá)到整體圖象的灰度感。黑白點(diǎn)的位置選擇稱(chēng)為圖案化。

下面介紹的一種設(shè)計(jì)標(biāo)準(zhǔn)圖案的算法，是由Limb在1969年提出的。

先以一個(gè)2×2的矩陣開(kāi)始：

通過(guò)遞歸關(guān)系有：

其中Mn和Un均為2n×2n的方陣，Un的所有元素都是1。
根據(jù)這個(gè)算法M2如下，為16級(jí)灰度的標(biāo)準(zhǔn)圖案：

M3(8×8陣)比較特殊，稱(chēng)為Bayer抖動(dòng)表。M4是一個(gè)16×16的矩陣。

M3 表模擬灰值圖像顯示效果：

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#pragma pack(1)   //全緊湊模式

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;
 }
 //讀入彩色bmp圖像文件頭，信息頭和圖像數(shù)據(jù)
 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;
  }
 }
 
 char savePath[]="D:\Temp\\save_test.bmp";
 FILE *f_save=fopen(savePath,"wb");
 if(f_save==NULL){
  perror("can not open file!");
  return -2;
 }

 fwrite(&b.bfHeader,sizeof(bitmapFileHeader),1,f_save);
 fwrite(&b.biHeader,sizeof(bitmapInfoHeader),1,f_save);
 fwrite(&b.palette,1024,1,f_save);
 fwrite(b.imgData,sizeof(unsigned char)*b.biHeader.biSizeImage,1,f_save);
 fclose(f_save);
 
 free(imageData);
 free(b.imgData);
 getchar();
 return 0;
}

代碼效果：

抖動(dòng)法

假設(shè)灰度級(jí)別的范圍從b(black)到w(white)，中間值t為(b+w)/2，對(duì)應(yīng)256級(jí)灰度，b=0,w=255,t=127.5。設(shè)原圖中象素的灰度為g，誤差值為e，則新圖中對(duì)應(yīng)象素的值用如下的方法得到：

if g > t then
  打白點(diǎn)
  e=g-w
else 
  打黑點(diǎn)
  e=g-b
 3/8 × e 加到右邊的象素
 3/8 × e 加到上邊的象素
 1/4 × e 加到右上方的象素

實(shí)現(xiàn)代碼：

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#pragma pack(1)   //全緊湊模式

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;
 }
 //讀入彩色bmp圖像文件頭，信息頭和圖像數(shù)據(jù)
 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;
 double e,f;
 for(i=0;i<height;i++){
  for(j=0;j<width;j++){
   b.imgData[lineBytes*i+j]=imageData[lineBytes*i+j]; //拷貝數(shù)據(jù)
  }
 }
 
 for(i=0;i<height;i++){ 
  for(j=0;j<width;j++){ 
   temp=b.imgData[lineBytes*i+j];
   if(temp>128){
    b.imgData[lineBytes*i+j]=255;
    e=(float)(temp-255);
   }
   else{
    b.imgData[lineBytes*i+j]=0;
    e=(float)temp;
   }
   if(j<width-1){
    f=b.imgData[lineBytes*i+j+1];
    f+=3.0/8.0*e;
    b.imgData[lineBytes*i+j+1]=(unsigned char)f; //向右傳播
   }
   if(i<height-1){
    f=b.imgData[lineBytes*(i+1)+j];
    f+=3.0/8.0*e;
    b.imgData[lineBytes*(i+1)+j]=(unsigned char)f; //向上傳播
    f=b.imgData[lineBytes*(i+1)+j+1];
    f+=1.0/4.0*e;
    b.imgData[lineBytes*(i+1)+j+1]=(unsigned char)f; //向右上傳播
   }
  }
 }
 
 
 char savePath[]="D:\Temp\\save_test.bmp";
 FILE *f_save=fopen(savePath,"wb");
 if(f_save==NULL){
  perror("can not open file!");
  return -2;
 }

 fwrite(&b.bfHeader,sizeof(bitmapFileHeader),1,f_save);
 fwrite(&b.biHeader,sizeof(bitmapInfoHeader),1,f_save);
 fwrite(&b.palette,1024,1,f_save);
 fwrite(b.imgData,sizeof(unsigned char)*b.biHeader.biSizeImage,1,f_save);
 fclose(f_save);
 
 free(imageData);
 free(b.imgData);
 getchar();
 return 0;
}

代碼效果：