Method untuk membuat histogram citra

/*

Pastikan sudah memasukan pustaka berikut ini ke dalam project:
+ jfreechart-1.0.19.jar
+ jcommon-1.0.23.jar

*/

// Method untuk membuat histogram
    public void bikinHistogram(BufferedImage gmbr, String judul) {
        int lebar = gmbr.getWidth();
        int tinggi = gmbr.getHeight();
        int count[][] = new int[4][0x100];
        int merah = 0;
        int biru = 1;
        int hijau = 2;
        int total = lebar * tinggi;

        try {
            for (int x = 0; x < lebar; x++) {
                for (int y = 0; y < tinggi; y++) {

                    int rgb = gmbr.getRGB(x, y);
                    int merahGrey = (rgb >> 16) & 0xff;
                    int hijauGrey = (rgb >> 8) & 0xff;
                    int biruGrey = (rgb >> 0) & 0xff;
                    int grey = (merahGrey + hijauGrey + biruGrey) / 3;

                    count[merah][merahGrey]++;
                    count[biru][biruGrey]++;
                    count[hijau][hijauGrey]++;
                    count[3][grey]++;

                }
            }
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }

        // membuat dataset dan mengisinya dengan perulangan
        DefaultCategoryDataset dataset = new DefaultCategoryDataset();

        for (int f = 0; f < 0x100; f++) {
            dataset.addValue(count[0][f], "Red", new Integer(f));
            dataset.addValue(count[2][f], "Blue", new Integer(f));
            dataset.addValue(count[1][f], "Green", new Integer(f));
            dataset.addValue(count[3][f], "Black", new Integer(f));
        }

        JFreeChart histo = ChartFactory.createBarChart("Histogram Citra", "Nilai", "Frekuensi", dataset, 
                PlotOrientation.VERTICAL, true, true, false);
        ChartFrame frame = new ChartFrame("Histogram Citra", histo);
        histo.setBackgroundPaint(Color.white);
        final CategoryPlot plot = (CategoryPlot) histo.getPlot();
        plot.setBackgroundPaint(Color.WHITE);
        plot.setRangeMinorGridlinePaint(Color.white);

        frame.setSize(500, 300);
        frame.setLocation(380, 200);
        frame.setTitle(judul);
        frame.setVisible(true);

    }