filterdemo.java

这是一个用JAVA开发的Applet程序

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.awt.geom.AffineTransform;
import java.awt.font.TextLayout;

import javax.swing.*;
import java.net.URL;

public class FilterDemo extends JApplet {
  static boolean isStandAlone = false;
  private BufferedImage bi[];
  //定义尖锐化滤镜的数值
  public static final float[] SHARPEN3x3_3 = {0.f, -1.f,  0.f,
                                              -1.f,  5.f, -1.f,
                                              0.f, -1.f,  0.f};
  //Applet初始化方法
  public void init() {
    setBackground(Color.white);
    bi = new BufferedImage[4];
    String s[] = { "image1.jpg", "image2.jpg", "image1.jpg", "image2.jpg"};
    for ( int i = 0; i < bi.length; i++ ) {
      Image img = null;
      if(!isStandAlone){//Applet取得图像的方法
        img = getImage(getURL(s[i]));
      }else{            //Application取得图像的方法
        ImageIcon tempIcon = new ImageIcon(s[i]);
        img = tempIcon.getImage();
      }

      //使每一张图片正确经过滤镜处理
      try {
        MediaTracker tracker = new MediaTracker(this);
        tracker.addImage(img, 0);
        tracker.waitForID(0);
      }
      catch ( Exception e ) {
      }
      int iw = img.getWidth(this);
      int ih = img.getHeight(this);
      bi[i] = new BufferedImage(iw, ih, BufferedImage.TYPE_INT_RGB);
      Graphics2D big = bi[i].createGraphics();
      big.drawImage(img,0,0,this);
    }
  }

  public void paint(Graphics g) {
    //取得Graphics2D类,并且进行滤镜初始化设置
    Graphics2D g2 = (Graphics2D) g;
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
    g2.setRenderingHint(RenderingHints.KEY_RENDERING,
                        RenderingHints.VALUE_RENDER_QUALITY);

    int w = getSize().width;
    int h = getSize().height;
    g2.setColor(Color.black);
    float[][] data = {{0.1f, 0.1f, 0.1f, 0.1f, 0.2f, 0.1f, 0.1f, 0.1f, 0.1f},
                    SHARPEN3x3_3};
    String theDesc[] = { "无特效", "尖锐特效", "黄照片特效", "漂白"};

    //进入图片处理特效循环
    for ( int i = 0; i < bi.length; i++ ) {
      int iw = bi[i].getWidth(this);
      int ih = bi[i].getHeight(this);
      int x = 0, y = 0;

       //改变图片大小的类
      AffineTransform at = new AffineTransform();
      at.scale((w-14)/2.0/iw, (h-34)/2.0/ih);

      //使用BufferedImageOp类与BufferedImage类进行特效处理
      BufferedImageOp biop = null;
      BufferedImage bimg = new BufferedImage(iw,ih,BufferedImage.
                                             TYPE_INT_RGB);
      switch (i) {
        case 0 :
        case 1 :
          x = i==0?5:w/2+3; y = 15;
          Kernel kernel = new Kernel(3,3,data[i]);
          //尖锐特效类
          ConvolveOp cop = new ConvolveOp(kernel,
                                          ConvolveOp.EDGE_NO_OP,
                                          null);
          cop.filter(bi[i],bimg);
          biop = new AffineTransformOp(at,
                            AffineTransformOp.TYPE_NEAREST_NEIGHBOR);
          break;
        case 2 :
          x = 5; y = h/2+15;
          byte chlut[] = new byte[256];
          for ( int j=0;j<200 ;j++ )
              chlut[j]=(byte)(256-j);
          //变色特效类
          ByteLookupTable blut=new ByteLookupTable(0,chlut);
          LookupOp lop = new LookupOp(blut, null);
          lop.filter(bi[i],bimg);
          biop = new AffineTransformOp(at,
                                       AffineTransformOp.TYPE_BILINEAR);
          break;
        case 3 :
          x = w/2+3; y = h/2+15;
          //漂白特效类
          RescaleOp rop = new RescaleOp(1.5f,10.0f, null);
          rop.filter(bi[i],bimg);
          biop = new AffineTransformOp(at,
                                       AffineTransformOp.TYPE_BILINEAR);
      }
      //显示图片
      g2.drawImage(bimg,biop,x,y);
      TextLayout tl = new TextLayout(theDesc[i], g2.getFont(),
                                     g2.getFontRenderContext());
      tl.draw(g2, (float) x, (float) y-4);
    }
  }

  //取得图片文件完全地址的方法
  protected URL getURL(String filename) {
    URL codeBase = null;
    URL url = null;
    try{
      codeBase = this.getCodeBase();
      url = new URL(codeBase, filename);
      return url;
    }catch(Exception e){
      System.out.println("找不到提供的文件");
      return null;
    }
  }

  //Applet独立运行的程序
  public static void main(String s[]) {
    isStandAlone = true;
    JFrame f = new JFrame("图片特效");
    //窗口关闭时清空内存
    f.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {System.exit(0);}
    });
    JApplet applet = new FilterDemo();
    f.getContentPane().add("Center", applet);
    applet.init();
    f.pack();
    f.setSize(new Dimension(550,550));
    f.show();
  }
}