processorapp.java

java编程的一些Applets例子。值得深入研究一下。

/********************************************************************************
*  This code includes sample image filters built in Java and a demo applet using
*  some of their features. 
*  Please note: I also have advanced filters such as blur, sharpen, diffuse, etc.
*  but due to time constraints, I could not include them here. If you are 
*  interested in those or other filters, please contact me at [e-mail]
*
*  ALL CONTENTS COPYRIGHT 1996 KELLY DEMPSKI ([e-mail]). ALL RIGHTS RESERVED
********************************************************************************/

import java.awt.*;
import java.lang.*;
import java.awt.image.*;


/* this filter just copies images from one to another - not really a filter */
class CopyFilter extends RGBImageFilter 
{
	public CopyFilter(){}
	public int filterRGB(int x, int y, int rgb)
	{return rgb;}
}

/* This filter adjusts the brightnesses of one or all of the color channels, depending on the
  values specified in the constructor */ 
class AdjustBrightnessFilter extends RGBImageFilter 
{
	private int ChangeRed, ChangeGreen, ChangeBlue;
	public AdjustBrightnessFilter(int RedDelta, int GreenDelta, int BlueDelta)
	{
		ChangeRed = RedDelta;
		ChangeGreen = GreenDelta;
		ChangeBlue = BlueDelta;	
	}
	public int filterRGB(int x, int y, int rgb) 
	{
		Color CurrentColor = new Color(rgb);
		Color FinalColor = new Color(Math.min(255, Math.max(0, CurrentColor.getRed() + ChangeRed)), 
						     Math.min(255, Math.max(0, CurrentColor.getGreen() + ChangeGreen)),
						     Math.min(255, Math.max(0, CurrentColor.getBlue() + ChangeBlue)));
		return FinalColor.getRGB();
      }
}

/* This filter adjusts the contrast of one or all of the color channels, depending on the
  values specified in the constructor */ 
class AdjustContrastFilter extends RGBImageFilter 
{
	private int ChangeRed, ChangeGreen, ChangeBlue;
	public AdjustContrastFilter(int RedDelta, int GreenDelta, int BlueDelta)
	{
		ChangeRed = RedDelta;
		ChangeGreen = GreenDelta;
		ChangeBlue = BlueDelta;	
	}
	public int filterRGB(int x, int y, int rgb) 
	{
		Color CurrentColor = new Color(rgb);
		int Red = CurrentColor.getRed();
		int Green = CurrentColor.getGreen();
		int Blue = CurrentColor.getBlue();

		if ((Red > 128) && (ChangeRed > 0)) { Red = Math.min(Red + ChangeRed, 255);}
		if ((Red > 128) && (ChangeRed < 0)) { Red = Math.max(Red + ChangeRed, 128);}
		if ((Red < 128) && (ChangeRed > 0)) { Red = Math.max(Red - ChangeRed, 0);}
		if ((Red < 128) && (ChangeRed < 0)) { Red = Math.min(Red - ChangeRed, 128);}
		if ((Green > 128) && (ChangeGreen > 0)) { Green = Math.min(Green + ChangeGreen, 255);}
		if ((Green > 128) && (ChangeGreen < 0)) { Green = Math.max(Green + ChangeGreen, 128);}
		if ((Green < 128) && (ChangeGreen > 0)) { Green = Math.max(Green - ChangeGreen, 0);}
		if ((Green < 128) && (ChangeGreen < 0)) { Green = Math.min(Green - ChangeGreen, 128);}
		if ((Blue > 128) && (ChangeBlue > 0)) { Blue = Math.min(Blue + ChangeBlue, 255);}
		if ((Blue > 128) && (ChangeBlue < 0)) { Blue = Math.max(Blue + ChangeBlue, 128);}
		if ((Blue < 128) && (ChangeBlue > 0)) { Blue = Math.max(Blue - ChangeBlue, 0);}
		if ((Blue < 128) && (ChangeBlue < 0)) { Blue = Math.min(Blue - ChangeBlue, 128);}

		Color FinalColor = new Color(Red, Green, Blue); 
		return FinalColor.getRGB();
      }
}

/* This filter changes the image to grayscale */
class GrayscaleFilter extends RGBImageFilter 
{
	public GrayscaleFilter(){}
	public int filterRGB(int x, int y, int rgb) 
	{
		Color CurrentColor = new Color(rgb);
		int ColorAverage = (CurrentColor.getRed() + CurrentColor.getGreen() + CurrentColor.getBlue())/3;
		Color FinalColor = new Color(ColorAverage, ColorAverage, ColorAverage);
		return FinalColor.getRGB();
      }
}

/* This filter creates the interesting effect caused by reexposing film midway in the developing process*/
class SolarizeFilter extends RGBImageFilter 
{
	public SolarizeFilter(){}
	public int filterRGB(int x, int y, int rgb) 
	{
		Color CurrentColor = new Color(rgb);
		int Red = CurrentColor.getRed();
		int Green = CurrentColor.getGreen();
		int Blue = CurrentColor.getBlue();

		if (Red > 128) {Red = 255 - Red;}
		if (Green > 128) {Green = 255 - Green;}
		if (Blue  > 128) {Blue = 255 - Blue;}

		Color FinalColor = new Color(Red, Green, Blue);
		return FinalColor.getRGB();
      }
}

/* This filter adjusts the colors of the image in HSB color space*/
class AdjustHSBFilter extends RGBImageFilter 
{
	private float HChange, SChange, BChange; 
	public AdjustHSBFilter(float HDelta, float SDelta, float BDelta)
	{
		HChange = HDelta;
		SChange = SDelta;
		BChange = BDelta;
	}
	public int filterRGB(int x, int y, int rgb) 
	{
		Color CurrentColor = new Color(rgb);
		float HSBVals[] = new float[3];
		Color.RGBtoHSB(CurrentColor.getRed(), CurrentColor.getGreen(), CurrentColor.getBlue(), HSBVals);
		HSBVals[0] = HSBVals[0] + HChange;
		HSBVals[1] = Math.min(HSBVals[1] + SChange, 1);
		HSBVals[2] = Math.min(1, Math.max(0, HSBVals[2] + BChange));

		if (HSBVals[1] <= 0) 
		{
			HSBVals[0] += .5;
			HSBVals[1] = Math.abs(HSBVals[1]);
		}

		if (HSBVals[0] >= 1) {HSBVals[0] -= (int)HSBVals[0];}
		if (HSBVals[0] <= 0) {HSBVals[0] += 1;}

		return Color.HSBtoRGB(HSBVals[0], HSBVals[1], HSBVals[2]);
      }
}


/* This filter creates a negative of the image*/
class NegativeFilter extends RGBImageFilter 
{
	public NegativeFilter(){}
	public int filterRGB(int x, int y, int rgb) 
	{
		Color CurrentColor = new Color(rgb);
		int Red, Green, Blue; 

		Red = Math.abs(CurrentColor.getRed() - 255);
		Green = Math.abs(CurrentColor.getGreen() - 255);
		Blue = Math.abs(CurrentColor.getBlue() - 255);

		Color FinalColor = new Color(Red, Green, Blue);
		return FinalColor.getRGB();
      }
}



/* the actual applet */
final public class ProcessorApp extends java.applet.Applet
{
 	Graphics     CurrentG;
 	Image        BaseImage;
	Panel 	 ButtonPanel;
	Button       BrightUpBtn, BrightDownBtn, ConUpBtn, ConDownBtn, GrayBtn, NegBtn, BlurBtn, OtherBtn;
	ImageFilter	 CurrentImageFilter;
	Image		 FilteredImage;

	/* set everything up. notice the image name is hard coded for now */
 	public void init()
 	{
		CurrentG = getGraphics(); 
		SetUpApp();
  		BaseImage = getImage(getDocumentBase(), "test.gif");
		CurrentImageFilter = new CopyFilter();
        	FilteredImage = createImage(new FilteredImageSource(BaseImage.getSource(),
                                                        CurrentImageFilter));
 	}

	/* lay out buttons, etc. */
	public void SetUpApp()
	{
		setLayout(new BorderLayout());
		ButtonPanel = new Panel();
		ButtonPanel.setLayout(new GridLayout(8,1));

		BrightUpBtn =   new Button("Bright +");
		BrightDownBtn = new Button("Bright -");
		ConUpBtn =      new Button("Contrast +");
		ConDownBtn =    new Button("Contrast -");
		GrayBtn =       new Button("Gray");
		NegBtn  =       new Button("Negative");
		BlurBtn =       new Button("Solarize");
		OtherBtn =      new Button("Hue +");

		ButtonPanel.add(BrightUpBtn);
		ButtonPanel.add(BrightDownBtn);
		ButtonPanel.add(ConUpBtn);
		ButtonPanel.add(ConDownBtn);
		ButtonPanel.add(GrayBtn);
		ButtonPanel.add(NegBtn);
		ButtonPanel.add(BlurBtn);
		ButtonPanel.add(OtherBtn);

		add("West",ButtonPanel);
	}

	/* handle the click of a button */
	public boolean handleEvent(Event evt)
	{
		if(evt.target instanceof Button)
		{
			String BtnLabel = ((Button)evt.target).getLabel();
			
			if(BtnLabel.equals("Bright +"))
				CurrentImageFilter = new AdjustBrightnessFilter(50, 50, 50);

			if(BtnLabel.equals("Bright -"))
				CurrentImageFilter = new AdjustBrightnessFilter(-50, -50, -50);

			if(BtnLabel.equals("Contrast +"))
				CurrentImageFilter = new AdjustContrastFilter(50, 50, 50);

			if(BtnLabel.equals("Contrast -"))
				CurrentImageFilter = new AdjustContrastFilter(50, 50, 50);

			if(BtnLabel.equals("Gray"))
				CurrentImageFilter = new GrayscaleFilter();

			if(BtnLabel.equals("Negative"))
				CurrentImageFilter = new NegativeFilter();

			if(BtnLabel.equals("Solarize"))
				CurrentImageFilter = new SolarizeFilter();

			if(BtnLabel.equals("Hue +"))
				CurrentImageFilter = new AdjustHSBFilter((float).5, (float)0, (float)0);

			FilteredImage = createImage(new FilteredImageSource(BaseImage.getSource(),
                                              CurrentImageFilter));

  			paint(CurrentG);
		}
  		return true;
	}

	public void paint(Graphics g)
	{
		CurrentG.drawImage(BaseImage, 410, 0, this);
		CurrentG.drawImage(FilteredImage, 100, 0, this);
	}
}