import java.awt.*;
 import java.awt.image.*;
 import javax.swing.*;
 /**
  * OFImage is a class that defines an image in OF (Objects First) format.
  *
  * @author Michael Kolling and David J. Barnes
  * @version 1.1
  */
 public class OFImage extends BufferedImage
 {
   /**
    * Create an OFImage copied from a BufferedImage.
    * @param image The image to copy.
    */
   public OFImage(BufferedImage image)
   {
      super(image.getColorModel(), image.copyData(null),
         image.isAlphaPremultiplied(), null);
   }
   /**
    * Create an OFImage with specified size and unspecified content.
    * @param width The width of the image.
    * @param height The height of the image.
    */
   public OFImage(int width, int height)
   {
     super(width, height, TYPE_INT_RGB);
   }
   /**
    * Set a given pixel of this image to a specified color. The
    * color is represented as an (r,g,b) value.
    * @param x The x position of the pixel.
    * @param y The y position of the pixel.
    * @param col The color of the pixel.
    */
   public void setPixel(int x, int y, Color col)
   {
     int pixel = col.getRGB();
     setRGB(x, y, pixel);
   }
   /**
    * Get the color value at a specified pixel position.
    * @param x The x position of the pixel.
    * @param y The y position of the pixel.
    * @return The color of the pixel at the given position.
    */
   public Color getPixel(int x, int y)
   {
     int pixel = getRGB(x, y);
     return new Color(pixel);
   }
   /**
    * Make this image a bit darker.
    */
   public void darker()
   {
     int height = getHeight();
     int width = getWidth();
     for(int y = 0; y < height; y++) {
       for(int x = 0; x < width; x++) {
         setPixel(x, y, getPixel(x, y).darker());
       }
     }
   }
   /**
    * Make this image a bit lighter.
    */
   public void lighter()
   {
     int height = getHeight();
     int width = getWidth();
     for(int y = 0; y < height; y++) {
       for(int x = 0; x < width; x++) {
         setPixel(x, y, getPixel(x, y).brighter());
       }
     }
   }
   /**
    * Perform a three level threshold operation.
    * That is: repaint the image with only three color values:
    *     white, gray, and black.
    */
   public void threshold()
   {
     int height = getHeight();
     int width = getWidth();
     for(int y = 0; y < height; y++) {
       for(int x = 0; x < width; x++) {
         Color pixel = getPixel(x, y);
         int brightness = (pixel.getRed() + pixel.getBlue() + pixel.getGreen()) / 3;
         if(brightness <= 85) {
           setPixel(x, y, Color.BLACK);
         }
         else if(brightness <= 170) {
           setPixel(x, y, Color.GRAY);
         }
         else {
           setPixel(x, y, Color.WHITE);
         }
       }
     }
   }
 }