Java中的色度鍵效果

Question

我還需要找到一個允許在Java中實現「色度鍵」效果的庫。該視頻包含一些綠色部分，在渲染過程中將其替換爲一張圖片以創建新視頻。

我正在將我的問題與已回答的類似問題聯繫起來，但回答不完整（Looking for Chromakey library in Java）。你能否指定你是如何做到這樣做的？幾個月來，我一直未能成功解決同一問題。

c00kiemon5ter指出幾種資源：

• JavaCV
• JAI（Java高級圖像API）
• Java圖像處理食譜

哪一個爲你所做的工作？

Answer 1

JavaCV包含很多處理視頻流的方法。

這段代碼應該讓你開始：http://tech.groups.yahoo.com/group/OpenCV/message/59118但是它在Java中可能太慢了。嘗試這種方法：

創建一個過濾器，將所有綠色像素轉換爲蒙版（查找「按顏色選擇」）。

使用蒙版將背景圖像複製到視頻中。

Answer 2

我想貢獻一段代碼，它給了我相當好的結果。我想知道我是否使用了Aaron Digulla建議的類和方法。

請注意，在這種情況下，我的視頻有黑色背景，這就是爲什麼我用背景圖像替換黑色。我希望獲得更好的結果，因爲我可以編輯視頻以獲得綠色背景，因爲黑色更有可能用在視頻主要角色中，並且替換錯誤的像素會導致相當糟糕的效果。

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package transparentvideo; 

import java.awt.BorderLayout; 
import java.awt.Color; 
import java.awt.Component; 
import java.awt.Container; 
import java.awt.Dimension; 
import java.awt.Graphics2D; 
import java.awt.Image; 
import java.awt.Rectangle; 
import java.awt.Toolkit; 
import java.awt.image.BufferedImage; 
import java.awt.image.FilteredImageSource; 
import java.awt.image.ImageFilter; 
import java.awt.image.ImageProducer; 
import java.awt.image.RGBImageFilter; 
import java.io.File; 
import javax.media.Manager; 
import javax.media.Player; 
import javax.swing.ImageIcon; 
import javax.swing.JComponent; 
import javax.swing.JFrame; 
import javax.swing.JLabel; 
import javax.swing.JPanel; 


public class TransparentVideo 
{ 
Player mediaPlayer; 

JFrame invisibleFrame; 
JFrame visibleFrame; 
JLabel videoScreen; 
JPanel offScreenVideo; 

String backgroundImageFile="nature.jpg"; 

String videoFile="girl.mov"; 

public TransparentVideo() 
{ 

    invisibleFrame = new JFrame(); 

    invisibleFrame.setSize(400, 400); 

    Container container=invisibleFrame.getContentPane(); 
    offScreenVideo = getvidComp(); 
    offScreenVideo.setPreferredSize(container.getSize()); 
    offScreenVideo.setVisible(true); 

    container.add(offScreenVideo); 
    invisibleFrame.setVisible(true); 

    visibleFrame=new JFrame(); 
    visibleFrame.setSize(container.getSize()); 
    visibleFrame.setLocationRelativeTo(null); 

    videoScreen = new JLabel(); 

    visibleFrame.getContentPane().add(videoScreen); 

    visibleFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    visibleFrame.setVisible(true); 

    invisibleFrame.setVisible(false); 

    try 
    { 
     while(true) 
     { 

      if(mediaPlayer.getState()==Player.Started) 
       reDraw(); 
      Thread.sleep(100); 
     } 
    } 
    catch (Exception ex) 
    { 
     System.out.println(ex.getMessage()); 
    } 
} 


public void reDraw() 
{ 
     BufferedImage bi=new BufferedImage(videoScreen.getWidth(), videoScreen.getHeight(), 
       BufferedImage.TYPE_INT_ARGB); 

     bi.getGraphics().drawImage(new ImageIcon(backgroundImageFile).getImage(), 0 , 0 , 
       videoScreen.getWidth(), videoScreen.getHeight(), null); 

     BufferedImage screenShot = createImage((JComponent) offScreenVideo, 
       new Rectangle(invisibleFrame.getBounds())); 
     Image im = makeColorTransparent(new ImageIcon(screenShot).getImage(), Color.BLACK); 

     bi.getGraphics().drawImage(im, 0 ,0 , videoScreen.getWidth(), videoScreen.getHeight(), null); 

     videoScreen.setIcon(new ImageIcon(bi)); 

} 



public static BufferedImage createImage(Component component, Rectangle region) 
{ 

    if (!component.isDisplayable()) { 
     Dimension d = component.getSize(); 

     if (d.width == 0 || d.height == 0) { 
      d = component.getPreferredSize(); 
      component.setSize(d); 
     } 

     layoutComponent(component); 
    } 

    BufferedImage image = new BufferedImage(region.width, region.height, BufferedImage.TYPE_INT_RGB); 
    Graphics2D g2d = image.createGraphics(); 

    if (!component.isOpaque()) 
    { 
     g2d.setColor(component.getBackground()); 
     g2d.fillRect(region.x, region.y, region.width, region.height); 
    } 

    g2d.translate(-region.x, -region.y); 
    component.paint(g2d); 
    g2d.dispose(); 
    return image; 
} 


public static void layoutComponent(Component component) 
{ 
    synchronized (component.getTreeLock()) 
    { 
     component.doLayout(); 

     if (component instanceof Container) 
     { 
      for (Component child : ((Container) component).getComponents()) 
      { 
       layoutComponent(child); 
      } 
     } 
    } 
} 


public JPanel getvidComp() 
{ 

     Manager.setHint(Manager.LIGHTWEIGHT_RENDERER,true); 

     try 
     { 
      mediaPlayer = Manager.createRealizedPlayer(new File(videoFile).toURL()); 

      mediaPlayer.realize(); 

      mediaPlayer.prefetch(); 

      JPanel video=new JPanel(new BorderLayout()); 
      video.add(mediaPlayer.getVisualComponent()) ; 

      mediaPlayer.start(); 

      return video; 

     } 

     catch(Exception d) 
     { 
      return null; 

     } 
} 



public static Image makeColorTransparent(Image im, final Color color) 
{ 
    ImageFilter filter = new RGBImageFilter() 
    { 
      public int markerRGB = color.getRGB() | 0xFF000000; 


      public final int filterRGB(int x, int y, int rgb) 
      { 
       Color c=new Color(rgb); 

       int red=c.getRed(); 
       int green=c.getGreen(); 
       int blue=c.getBlue(); 

       //if(red<140 && green<140 && blue<140) 
       { 
        int alpha=Math.max(Math.max(red , green), Math.max(green, blue))*3; 
        c=new Color(red , green , blue , alpha>255 ?255 :alpha); 
       } 

       return c.getRGB(); 
      } 
     }; 

    ImageProducer ip = new FilteredImageSource(im.getSource(), filter); 
    return Toolkit.getDefaultToolkit().createImage(ip); 
} 


public static void main(String[] args) { 
    new TransparentVideo(); 
} 

}