本文实例为大家分享了c语言实现二值图像模拟灰值图像显示效果的具体代码，供大家参考，具体内容如下
图案法
图案法(patterning)是指灰度可以用一定比例的黑白点组成的区域表示，从而达到整体图象的灰度感。黑白点的位置选择称为图案化。
下面介绍的一种设计标准图案的算法，是由limb在1969年提出的。
先以一个2×2的矩阵开始：
通过递归关系有：
其中mn和un均为2n×2n的方阵，un的所有元素都是1。
根据这个算法m2如下，为16级灰度的标准图案：
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;
}
}
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;
}
代码效果：
抖动法
假设灰度级别的范围从b(black)到w(white)，中间值t为(b+w)/2，对应256级灰度，b=0,w=255,t=127.5。设原图中象素的灰度为g，误差值为e，则新图中对应象素的值用如下的方法得到：
if g > t then 打白点 e=g-w else 打黑点 e=g-b 3/8 × e 加到右边的象素 3/8 × e 加到上边的象素 1/4 × e 加到右上方的象素
实现代码：
#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;
double e,f;
for(i=0;i<height;i++){
for(j=0;j<width;j++){
b.imgdata[linebytes*i+j]=imagedata[linebytes*i+j]; //拷贝数据
}
}
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; //向右传播
}
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; //向上传播
f=b.imgdata[linebytes*(i+1)+j+1];
f+=1.0/4.0*e;
b.imgdata[linebytes*(i+1)+j+1]=(unsigned char)f; //向右上传播
}
}
}
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;
}
代码效果：
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
