Class SobelOperator extends ImageProcessing

import ij.fach.FilterValue;

import java.awt.Color;
import java.awt.image.BufferedImage;
import java.util.ArrayList;

public class SobelOperator extends ImageProcessing {

    public static String IDENTIFIER = "Sobel-Operator";

    private String ACTIVITY = "Activity";
    private boolean isActiveThreshold = false;
    private String THRESHOLD = "Threshold";
    private int threshold = 40;

    public SobelOperator(BufferedImage input, ArrayList<FilterValue> para) {
        super(input, para);

        Object o = getParameter(THRESHOLD);
        if (o != null)
            threshold = new Integer(o.toString());

        o = getParameter(ACTIVITY);
        if (o != null)
            isActiveThreshold = new Boolean(o.toString());
    }

    public SobelOperator(int width, int height, int type, int maxValue,
            int[] input) {
        super(width, height, type, maxValue, input);
    }

    @Override
    public void processing() {
        int sum, sumX, sumY;

        int[] array = pixelOrg;
        int[] newArray = pixelNew;

        for (int i = 0; i < height; i++) { // Zeilenschleife
            for (int j = 0; j < width; j++) { // Spaltenschleife
                //pixelNew[y * width + x] = pixelOrg[y * width + x];


                if (i > 0 && j > 0 && i < height - 1 && j < width - 1) {
                   // Gx=f(x+1,y-1)+2f(x+1,y)+f(x+1,y+1)-(f(x-1,y-1)+2f(x-1,y)+f(x-1,y+1))

                    sumX = array[(i + 1) * width + j - 1] + 2 * array[(i + 1)* width + j] + array[(i + 1)*width + j + 1] -
                            (array[(i - 1)*width + j - 1] + 2 * array[(i-1)*width + j] + array[(i - 1)*width + j + 1]);

                    // Gy=f(x-1,y+1)+2f(x,y+1)+f(x+1,y+1)-(f(x-1,y-1)+2f(x,y-1)+f(x+1,y-1))

                    sumY = array[(i - 1)*width + j + 1] + 2 * array[i*width + j + 1] + array[(i + 1)*width + j + 1] -
                            (array[(i - 1)*width + j - 1] + 2 * array[i*width + j-1] + array[(i + 1)*width + j - 1]);

                    sum = (int) Math.sqrt(sumX * sumX + sumY * sumY);

                    newArray[i*width + j] = sum > 0xff ? 0xff : sum;

                } else if (i < height - 1 && j < width - 1) {
                    //Gx=f(x+1,y+1)-f(x,y),
                    //Gy=f(x,y+1)-f(x+1,y)
                    sumX = array[(i+1) * width + j + 1] - array[i*width + j];
                    sumY = array[i*width + j + 1] - array[(i+1)*width + j];
                    sum = (int) Math.sqrt(sumX * sumX + sumY * sumY);
                    newArray[i*width + j] = sum > 0xff ? 0xff : sum;
                } else if (j == width - 1) {
                                         //last row
                    newArray[i*width + j] = newArray[i*width + j - 1];
                } else if (i == height - 1) {
                                         //the last line
                    newArray[i*width + j] = newArray[(i - 1)*width + j];
                }

            }
        }
    }
}