Question

I had load buffered image and need to plot histogram? please suggest me next steps to to plot
RGB histogram. if it can done using jai please suggest me the way to do it. I hadtried alot and also googled alot but dint found any right solution.
here is how i had load my image please provide me next steps

    BufferedImage   image= ImageIO.read(new File("C:\\Images\\Sunset.jpg"));             

    ParameterBlock pb = new ParameterBlock();

    int[] bins = { 256 };
    double[] low = { 0.0D };
    double[] high = { 256.0D };

    pb.addSource(image);
    pb.add(null);
    pb.add(1);
    pb.add(1);
    pb.add(bins);
    pb.add(low);
    pb.add(high);

    RenderedOp op = JAI.create("histogram", pb, null);
    Histogram histogram = (Histogram) op.getProperty("histogram");

Answer 1

import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.awt.image.RescaleOp;
import java.io.IOException;
import javax.media.jai.JAI;
import javax.media.jai.PlanarImage;
import javax.swing.*;

public class FinalHistogram extends JPanel {

    int[] bins = new int[256];
    FinalHistogram(int[] pbins) {
        bins = pbins;
        repaint();
    }

    @Override
    protected void paintComponent(Graphics g) {        
        for (int i = 0; i < 256; i++) {
            System.out.println("bin[" + i + "]===" + bins[i]);
            g.drawLine(200 + i, 300, 200 + i, 300 - (bins[i])/1000);
        }
    }


    public static void main(String[] args) throws IOException {
        JFrame frame = new JFrame();
        frame.setSize(500, 500);
        int[] pbins = new int[256];
        int[] sbins = new int[256];
        PlanarImage image = JAI.create("fileload", "image12.tiff");
        BufferedImage bi = image.getAsBufferedImage();    
        System.out.println("tipe is          " + bi.getType());
        int[] pixel = new int[3];

        int k = 0;
        Color c = new Color(k);
        Double d = 0.0;
        Double d1;
        for (int x = 0; x < bi.getWidth(); x++) {
            for (int y = 0; y < bi.getHeight(); y++) {
                pixel = bi.getRaster().getPixel(x, y, new int[3]);
                d=(0.2125*pixel[0])+(0.7154*pixel[1])+(0.072*pixel[2]);
                k=(int) (d/256);
                sbins[k]++;
            }
        }
        System.out.println("copleted" + d + "--" + k);
        JTabbedPane jtp=new JTabbedPane();
        ImageIcon im= new ImageIcon(bi);
        jtp.addTab("Histogram",new FinalHistogram(sbins));
        frame.add(jtp);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    }
}