import java.awt.*;
import java.awt.image.*;
import javax.imageio.ImageIO;
import java.io.File;
import java.io.IOException;
class Main {

static void pb(byte[] x){for(int k=0; k<x.length; ++k) System.out.print(" "+x[k]);}

    static public void main(String[] args){
      try {BufferedImage I = ImageIO.read(new File(args[0]));
        WritableRaster wr = I.getRaster();
        int nde = wr.getNumDataElements(), tt = wr.getTransferType();
        System.out.println("Here: bnds="+wr.getBounds()
          +", numDataElements="+nde+", tt="+tt);
        System.out.println("isa: "+
         ((wr.getDataElements(0, 0, null)).getClass()).getCanonicalName());
        byte[] ba = (byte[])wr.getDataElements(0, 0, null);
        System.out.println("Has "+ba.length+" bytes.");
        for(int i=0; i<4; ++i) for(int j=0; j<4; ++j) {
          pb((byte[])wr.getDataElements(i+300, j+300, null));
          System.out.println(" "+i+" "+j);}
        {int n = 3*20*20; byte[] bc= new byte[n];
          for(int j=0; j<n; ++j) bc[j]=0;
          wr.setDataElements(I.getWidth()/2-10, I.getHeight()/2-10, 20, 20, bc);}
        try {ImageIO.write(I, "jpg", new File(args[1]));}
        catch (IOException e) {System.err.println("image not saved.");}}
      catch (IOException e) {System.err.println("File not read.");}}}