4

画面をキャプチャしてから、画像をスケーリングしながら再帰的に画像をJFrameにペイントしようとしています(鏡の中の鏡を見たときに得られる効果を作成するため)。

コードに問題があります - グラフィックが描画されません。私は何を間違っていますか?

import java.awt.AWTException;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.HeadlessException;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferedImage;

import javax.swing.JFrame;


public class ScreenCapture extends JFrame {

    BufferedImage screenCapture;
    Graphics screenCaptureGraphics;
    private static int recurseCount = 0;
    private static float $scale = 0.9f;
    private static float scale = 1.0f;
    private static int height;
    private static int width;

    ScreenCapture() {
        try {
            screenCapture = new Robot().createScreenCapture(
                       new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()) );
            height = screenCapture.getHeight();
            width = screenCapture.getWidth();
            setSize(new Dimension(width, height));
            addWindowListener(new LocalWindowListener());
            Graphics g = recursiveDraw(screenCapture, getGraphics());
            paint(g);
        } catch (HeadlessException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (AWTException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    private Graphics recursiveDraw(BufferedImage img, Graphics imgG) {
        updateScale(++recurseCount);
        float newWidth = scale*width;
        float newHeight = scale*height;
        int w = (int) newWidth;
        int h = (int) newHeight;
        System.out.println("W: " + w + "; H: " + h);
        if (w >= 10 && h >= 10) {
            //scale image
            System.out.print("Creating scaled Image...");
            Image scaled = img.getScaledInstance(w, h, Image.SCALE_SMOOTH);
            BufferedImage resized = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
            imgG = resized.createGraphics();
            imgG.drawImage(scaled, 0, 0, null);
            System.out.println("...Image drawn to graphics");
            //return new graphics
            return recursiveDraw(resized, imgG);
        } else {
            //otherwise return old graphics
            System.out.println("Completed.");
            return imgG;
        }
    }


    private void updateScale(int count) {
        for (int i=0; i<count; i++) {
            scale *= $scale;
        }
        System.out.println("Updated scale: " + scale + "; Recurse count: " + recurseCount);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new ScreenCapture().setVisible(true);
            }
        });
    }

    private class LocalWindowListener extends WindowAdapter {
        @Override
        public void windowClosing(WindowEvent e) {
            System.exit(0); return;
        }
    }

}

編集: これは、@ andrew-thompson の回答の後に試したものです:

ScreenCapture() {
    try {
        screenCapture = new Robot().createScreenCapture(
                   new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()) );
        height = screenCapture.getHeight();
        width = screenCapture.getWidth();
        setSize(new Dimension(width, height));
        addWindowListener(new LocalWindowListener());
        setLayout(new GridLayout());
        add(new PaintPanel());
    } catch (HeadlessException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (AWTException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

private class PaintPanel extends JPanel {
    @Override
    public void paintComponent(Graphics g) {
        g=recursiveDraw(screenCapture, g);
        //what to do with g?
    }
}

BufferedImage をグラフィックスにペイントする方法がわからないという同じ問題がまだあります。

4

4 に答える 4

6

Swingコードを再帰的な画像作成コードから分離します。実際、BufferedImageを作成して返す静的メソッドを作成し、Swingコードを含まないことを検討してください。次に、必要に応じてGUIでメソッドを呼び出し、画像を取得してディスクに書き込むか、JLabelのImageIconに表示します。

これを行ったとき(実際には今日)、このシグネチャを使用して再帰メソッドを作成しました

private static void recursiveDraw(BufferedImage img, Graphics imgG, double scale) { 

このメソッド本体を使用して(擬似コードで)

start recursiveDraw method 
   // most important: all recursions must have a good ending condition: 
   get img height and width. If either <= a min, return 
   create a BufferedImage, smlImg, for the smaller image using the height, 
        width and scale factor 
   Get the Graphics object, smlG, from the small image 
   Use smlG.drawImage(...) overload to draw the big image in shrunken 
        form onto the little image 
   recursively call recursiveDraw passing in smlImg, smlG, and scale. 
   dispose of smlG 
   draw smlImg (the small image) onto the bigger one using the bigger's 
        Graphics object (passed into this method) and a different 
        overload of the drawImage method. 
end recursiveDraw method

このアルゴリズムにより、次のような画像が生成されました。ここに画像の説明を入力してください

例えば:

import java.awt.*;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.image.BufferedImage;
import javax.swing.*;

public class RecursiveDrawTest {
   private static final Color BACKGRND_1 = Color.green;
   private static final Color BACKGRND_2 = Color.MAGENTA;
   private static final Color FOREGRND_1 = Color.blue;
   private static final Color FOREGRND_2 = Color.RED;

   private static void createAndShowGui() {
      final JPanel mainPanel = new JPanel(new BorderLayout());
      final JSlider slider = new JSlider(50, 90, 65);
      slider.setMajorTickSpacing(10);
      slider.setMinorTickSpacing(5);
      slider.setPaintLabels(true);
      slider.setPaintTicks(true);

      JPanel southPanel = new JPanel();
      southPanel.add(new JLabel("Percent Size Reduction:"));
      southPanel.add(slider);
      southPanel.add(new JButton(new AbstractAction("Create Recursive Image") {

         @Override
         public void actionPerformed(ActionEvent arg0) {
            try {
               double scale = slider.getValue() / 100.0;
               BufferedImage img = createRecursiveImg(scale);
               ImageIcon icon = new ImageIcon(img);
               JLabel label = new JLabel(icon);

               Window win = SwingUtilities.getWindowAncestor(mainPanel);
               JDialog dialog = new JDialog(win, "Image", ModalityType.MODELESS);
               dialog.getContentPane().add(label);
               dialog.pack();
               dialog.setLocationRelativeTo(null);
               dialog.setVisible(true);
            } catch (AWTException e) {
               e.printStackTrace();
            }
         }
      }));

      mainPanel.add(new JScrollPane(new JLabel(new ImageIcon(createLabelImg()))), 
            BorderLayout.CENTER);
      mainPanel.add(southPanel, BorderLayout.PAGE_END);

      JFrame frame = new JFrame("RecursiveDrawTest");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

   // create a background image to display in a JLabel so that the GUI
   // won't be boring.
   private static BufferedImage createLabelImg() {
      Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
      int width = (5 * d.width) / 6;
      int height = (5 * d.height) / 6;
      BufferedImage img = new BufferedImage(width, height, 
            BufferedImage.TYPE_INT_ARGB);
      Graphics2D g2 = img.createGraphics();
      g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
      g2.setPaint(new GradientPaint(0, 0, BACKGRND_1, 40, 40, BACKGRND_2, true));
      g2.fillRect(0, 0, width, height);
      g2.setPaint(new GradientPaint(0, height, FOREGRND_1, 40, height - 40, FOREGRND_2, true));
      g2.fillOval(0, 0, 2 * width, 2 * height);
      g2.dispose();
      return img;
   }

   // non-recursive image to get the initial image that will be drawn recursively
   public static BufferedImage createRecursiveImg(double scale) throws AWTException {
      Robot robot = new Robot();
      Dimension screenSz = Toolkit.getDefaultToolkit().getScreenSize();
      Rectangle screenRect = new Rectangle(screenSz);
      BufferedImage img = robot.createScreenCapture(screenRect);
      Graphics g = img.getGraphics();
      recursiveDraw(img, g, scale); // call recursive method
      g.dispose();
      return img;
   }

   // recursive method to draw image inside of image
   private static void recursiveDraw(BufferedImage img, Graphics g, double scale) {
      int w = img.getWidth();
      int h = img.getHeight();

      int smlW = (int)(w * scale);
      int smlH = (int)(h * scale);
      // criteria to end recursion
      if (smlW <= 1 || smlH <= 1) {
         return; 
      }

      BufferedImage smlImg = new BufferedImage(smlW, smlH, BufferedImage.TYPE_INT_ARGB);
      Graphics smlG = smlImg.getGraphics();
      // draw big image in little image, scaled to little image
      smlG.drawImage(img, 0, 0, smlW, smlH, null);

      // recursive call
      recursiveDraw(smlImg, smlG, scale);
      smlG.dispose(); // clear resources when done with them

      // these guys center the smaller img on the bigger
      int smlX = (w - smlW) / 2;
      int smlY = (h - smlH) / 2;
      // draw small img on big img
      g.drawImage(smlImg, smlX, smlY, smlW, smlH, null);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}
于 2012-03-18T16:38:00.550 に答える
5
 Graphics g = recursiveDraw(screenCapture, getGraphics());

電話しないでくださいgetGraphics()paint(Graphics)1をオーバーライドして、提供されたGraphicsインスタンスを使用します。

  1. Swing を使用する場合、実際には aまたはのpaintComponent(Graphics)メソッドをオーバーライドするのが最善です。次に、それを最上位のコンテナーに追加します。JComponentJPanel
于 2012-03-18T14:35:51.900 に答える
2

これはあなたが望んでいるものですか:

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Robot;
import java.awt.Toolkit;

import java.awt.image.BufferedImage;

import javax.imageio.ImageIO;

import javax.swing.*;

public class CaptureScreen extends JPanel
{
    private BufferedImage screenShot;
    private JLabel imageLabel;
    private BufferedImage secondScreenShot;

    public void createAndDisplayGUI()
    {
        JFrame frame = new JFrame("CAPTURE SCREEN");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationByPlatform(true);

        //imageLabel = new JLabel();
        //getImageForLabel();
        //add(imageLabel);

        frame.getContentPane().add(this);
        frame.setSize(600, 600);
        frame.setVisible(true);
    }

    private void getImageForLabel()
    {
        Robot robot = null;
        try
        {
            robot = new Robot();
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }

        screenShot = robot.createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
        ImageIcon icon = new ImageIcon(screenShot);
        imageLabel.setIcon(icon);
    }

    public void paintComponent(Graphics g)
    {
        Robot robot = null;
        try
        {
            robot = new Robot();
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }

        screenShot = robot.createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
        secondScreenShot = getScaledImage((Image) screenShot, 300, 300);

        g.drawImage(screenShot, 0, 0, null);
        g.drawImage(secondScreenShot, 150, 150, null);
    }

    private BufferedImage getScaledImage(Image srcImg, int w, int h)
    {
        BufferedImage resizedImg = new BufferedImage(w, h, BufferedImage.TRANSLUCENT);
        Graphics2D g2 = resizedImg.createGraphics();
        g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
        g2.drawImage(srcImg, 0, 0, w, h, null);
        g2.dispose();
        return resizedImg;
    }

    public static void main(String... args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                new CaptureScreen().createAndDisplayGUI();
            }
        });
    }
}

出力は次のとおりです。

別のスクリーンショット

于 2012-03-18T15:15:23.770 に答える
1

再帰を取り除きます。適切なサイズの単一のバッファー イメージを作成し、そのための Graphics オブジェクトを作成します。ループを使用して、選択したしきい値まで段階的に縮小された画像を描画します。最後に、paintComponent() 内で g.drawImage() を使用して、画像を画面に描画します。再帰を維持する場合は、画像を渡し、縮小された画像を継続的にオーバーレイする必要があります。メソッドから何も返す必要はありません。

于 2012-03-18T15:22:50.153 に答える