import java.awt.*;
import java.awt.image.*;
import java.applet.*;
import java.net.*;
import java.io.*;
import java.lang.Math;
import java.util.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.JApplet;
import javax.imageio.*;
import javax.swing.event.*;

public class gaussianNoise {

		int[] input;
		int[] output;
		int progress;
		float variance;
		int width;
		int height;
		Random randgen;

		public void gaussianNoise() {
			progress=0;
		}
		
		public void init(int[] original, int widthIn, int heightIn, float varianceIn) {
			randgen = new Random();
			variance=varianceIn;
			width=widthIn;
			height=heightIn;
			input = new int[width*height];
			output = new int[width*height];
			input=original;
		}

		public int[] process() {
			double rand;
			int result = 0;

			for(int x=0; x<width;x++) {
				progress++;
				for(int y=0; y<height;y++) {

	  
					//Generate amount to be added
					rand = (variance*(randgen.nextGaussian()));      
					result = (int)((input[y*width+x] & 0xff) + rand);
		
					//Clip final result
					if (result < 0) {
						result = 0;
					} 
					else if (result > 255) {
						result = 255;
					}
	
					//Convert back to grayscale pixel
					output[y*width+x] = 0xff000000 | (result + (result << 16) + (result << 8));
				}
			}
			return output;
		}

		public int getProgress() {
			return progress;
		}


	}