zhifang.java

来自「使用JAVA程序语言」· Java 代码 · 共 50 行

import java.awt.*;
import java.awt.image.*;
import java.applet.*;

public class zhifang extends Applet
{
 Image img; 
 int W,H;
 int p[];
 int hist[]=new int[256];
 int max_hist=0;
 public  void init()
 {
  
  try
  {
   img=getImage(getDocumentBase(),"1.jpg");
   MediaTracker mt= new MediaTracker(this);
   mt.addImage(img,0);
   mt.waitForID(0);
   W=img.getWidth(null);
   H=img.getHeight(null);
   p=new int [W*H];
   PixelGrabber grabber=new PixelGrabber(img,0,0,W,H,p,0,W);
   grabber.grabPixels();
  }catch(InterruptedException e){};
  for(int n=0;n<W*H;n++)
  {
   int pixel=p[n];
   int r=0xff&(pixel>>16);
   int g=0xff&(pixel>>8);
   int b=0xff&(pixel);
   int m=(int)(0.33*r+0.56*g+0.11*b);
   hist[m]++;
  }
 }
 public void paint (Graphics g)
 {
  g.drawImage(img,50,0,400,300,null);
  g.drawLine(50,610,50,610);
  g.drawLine(50,610,550,610);
  int x=0,y=0;
  for(int n=0;n<256;n++)
  {
    x=50+2*n;
    y=610-(int)(hist[n]/30);
	g.drawLine(x,610,x,y);
  }
 }
}