import java.io.*;
import java.util.*;
import java.awt.*;
import java.awt.image.*;
import javax.imageio.*;

public class IO {

	
	
	public double[][] readImage(File f) {
	
		Panel panel = new Panel();
		Image image = Toolkit.getDefaultToolkit().getImage(f.getPath());
		MediaTracker mTracker = new MediaTracker(panel);
		mTracker.addImage(image,1);
		try {
			mTracker.waitForID(1);
		} catch (InterruptedException ie) {
			ie.printStackTrace();
		}
		int width = image.getWidth(null);
		int height = image.getHeight(null);
  	
		double[][] tempArray = new double[height][width];
		
		int pixels[] = new int [width * height];
		PixelGrabber pg = new PixelGrabber(image,0,0,width,height,pixels,0,width);
		try{ 
			pg.grabPixels();  
		} catch (InterruptedException ie) {
			ie.printStackTrace();
		}
		
		for (int i = 0; i < height; i++) {
			for (int j = 0; j < width; j++) {
				Color tempColor = new Color(pixels[j + (i*width)]);
				tempArray[i][j] = (tempColor.getRed() + tempColor.getGreen() + tempColor.getBlue())/ 3; 
			}
		}

		return tempArray;
		
	}
	
	
	
	
	
	
	public void writeJPEG(Image image, File f) {
	
	
		Panel panel = new Panel();
	    
	
	    // Make a Buffered image in memory.
	    
	    BufferedImage bi = new BufferedImage(image.getWidth(panel), image.getHeight(panel), BufferedImage.TYPE_INT_RGB);
	    
	    // Get the BufferedImage's 2D Graphics Context.
	    
	    Graphics2D g2d = bi.createGraphics();
    
	    // Draw the surface image to the buffered image.
	    
	    g2d.drawImage(image,0,0,panel);
    
	    // Get a rendered image.
	    
	    RenderedImage ri = (RenderedImage) bi;
	    
	    // Kill off the unneeded graphics context.
	    
	    g2d.dispose();
	    
	    // Now write the Jpeg.
	    
		String format = f.getPath();
		format = format.substring(format.lastIndexOf(".") + 1);

		// File format set depending on how the user has named the file to be 
		// saved.
	    try {
			ImageIO.write(ri, format, f);
	    } catch (Exception e) {
			System.out.println("Format not recognised: " + format);
		}
	 
	}
	
}