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Displaying Source Code(s)
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The Distance Transforn of a Binary Image
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Description : This is a image processing program which performs
the distance transform of a binary image.Distance transform is
widely used for image thinning and finding skeleton of an image.
//1:newfndistrans.java
//2:A bmp monochrome image(preferably 512-512)
//make the image from mspaint or any other source
import java.io.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class newfndistrans extends JFrame{
frame frm=null;
File f;
FileInputStream ff;
Color cl;
int count;
int a[];
int rnum,gnum;
int xsize;
int ysize;
final int sample=5;
String str=null;
newfndistrans(String str)
{
super(str);
frm=new frame();
count=0;
a=new int[8];
rnum=0;gnum=0;
}
public void paint(Graphics g)
{
int x,y,i=0,j=0,temp;
try{
System.out.println("Starting");
System.out.println("filename="+frm.getfilename());
try{f=frm.getfilename();
ff=new FileInputStream(f);
}catch(Exception e){
System.out.println("error in reading file");
}
ff.skip(18);
i=ff.read();
i=((ff.read()<<8)|i);
i=((ff.read()<<16)|i);
i=((ff.read()<<24)|i);
xsize=i;
System.out.println("width="+xsize);
i=0;
i=ff.read();
i=((ff.read()<<8)|i);
i=((ff.read()<<16)|i);
i=((ff.read()<<24)|i);
ysize=i;
System.out.println("Height="+ysize);
ff.skip(38);//62-(2+16+4+4=26)=36, actually total=62 Bytes
header
//note:make it 38 for nrectbit1.bmp and nrectbit2.bmp
x=0;y=ysize;
int pix[][],mat1[][];
pix=new int[xsize][ysize];
mat1=new int[xsize][ysize];
System.out.println("here");
while(true)
{
rnum=ff.read();
//System.out.println("rnum="+rnum);
if(rnum==-1)break;
count=7;
//image has 0 for black ,1 for white,but my convention is
opposite
while(rnum>0)
{
gnum=rnum%2;
if(gnum==0)a[count]=1;
else a[count]=0;
count--;
rnum=rnum/2;
}
while(count>=0)
{a[count]=1;count--;
}
for(i=0;i<=7;i++)
{if(a[i]==0)cl=new Color(255,255,255);
else cl=new Color(0,0,0);
pix[x][y-1]=a[i];
mat1[x][y-1]=a[i];
g.setColor(cl);
g.drawRect(x,y,1,1);
x++;
if(x==xsize){x=0;y--;}
}
}//end while
System.out.println("File read successfully");
//sleep for 4 seconds(4000 msec)
try{Thread.sleep(4000);
}catch(Exception e){}
//clear the region where the image was drawn,area near the
boundaries
are
also cleaned
for(j=0;j<=ysize+2;j++)
for(i=0;i<=xsize+2;i++)
g.clearRect(i,j,1,1);
//cleaning done above
//0 means white,1 means black
//perform the distance transform
for(j=0;j<ysize;j++)
for(i=0;i<xsize;i++)
{
if(mat1[i][j]==0)continue;
if((j==0)||(j==ysize-1)){mat1[i][j]=1;continue;}
if((i==0)||(i==xsize-1)){mat1[i][j]=1;continue;}
temp=findmin(mat1[i-1][j],mat1[i-1][j-1],mat1[i][j-1],mat1[i+1][j-1]);
mat1[i][j]=temp+1;
}
//perform the distance transform from bottom
for(j=ysize-1;j>=0;j--)
for(i=xsize-1;i>=0;i--)
{if(mat1[i][j]==0)continue;
if((j==0)||(j==ysize-1)){mat1[i][j]=1;continue;}
if((i==0)||(i==xsize-1)){mat1[i][j]=1;continue;}
temp=findmin(mat1[i-1][j+1],mat1[i][j+1],mat1[i+1][j+1],mat1[i+1][j]);
if(temp>(mat1[i][j]-1))temp=mat1[i][j]-1;
mat1[i][j]=temp+1;
}
int max=-9999,colornum,i1,j1,globmax=-9999;
x=0;y=0;
for(j=0;j<ysize-(ysize%sample);j+=sample)
for(i=0;i<xsize-(xsize%sample);i+=sample)
{
max=-9999;
for(j1=j;j1<j+sample;j1++)
for(i1=i;i1<i+sample;i1++)
if(max<mat1[i1][j1])
{
max=mat1[i1][j1];
//xcord=i1;ycord=j1;
}
//out of both above for loops
if(globmax<max)globmax=max;
if(max!=0)
{
System.out.println("max="+max);
for(j1=j;j1<j+sample;j1++)
for(i1=i;i1<i+sample;i1++)
mat1[i1][j1]=max;
}
}
System.out.println("globmax="+globmax);
for(j=0;j<ysize;j++)
for(i=0;i<xsize;i++)
{colornum=(mat1[i][j]*255)/globmax;//contrast enhancement
colornum=255-colornum;
cl=new Color(colornum,colornum,colornum);
g.setColor(cl);
g.drawRect(i,j,1,1);
}
ff.close();
System.out.println("program ends");
}//end try block
catch(Exception e)
{System.out.println("Error"+e.getMessage());
}
}
int findmin(int num1,int num2,int num3,int num4)
{
int min=4000;
if(min>num1)min=num1;
if(min>num2)min=num2;
if(min>num3)min=num3;
if(min>num4)min=num4;
return(min);
}
public static void main(String args[])
{
JFrame frm=new newfndistrans("Distance Transform");
frm.setSize(700,700);
frm.setVisible(true);
}//end main()
}// end class fndistrans
class frame extends JFrame{
JButton but;
JFileChooser fch;
String filename;
File file=null;
//Container con;
boolean temp;
frame()
{ super("FileReading");
setSize(700,500);
setLayout(new FlowLayout());
temp=true;
but=new JButton("Open the binary file");
add(but);
fch=new JFileChooser();
but.addMouseListener(new MouseAdapter()
{ public void mousePressed(MouseEvent me)
{
int retval=fch.showOpenDialog(but);
if(retval==JFileChooser.APPROVE_OPTION)
{
file=fch.getSelectedFile();
filename=file.getName();
System.out.println("1filename="+filename);
temp=false;
}
}
});
setVisible(true);
while(temp);
}//end constructor
File getfilename()
{System.out.println("filename="+filename);
return file;
} |
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123
Eng