get BufferedImage Histogram - Java 2D Graphics

Java examples for 2D Graphics:BufferedImage Effect

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Description

get BufferedImage Histogram

Demo Code

/*//  ww w  .ja  va 2 s .c  o  m
 * (C) Copyright 2000-2011, by Scott Preston and Preston Research LLC
 *
 *  Project Info:  http://www.scottsbots.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
import java.awt.Color;
import java.awt.Image;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.awt.image.renderable.ParameterBlock;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import javax.imageio.ImageIO;
import javax.media.jai.Histogram;
import javax.media.jai.JAI;
import javax.media.jai.PlanarImage;
import com.scottsbots.core.utils.Utils;

public class Main{
    public static int[] getHistogram(BufferedImage bufImg) {

        // Set up the parameters for the Histogram object.
        int[] bins = { 256, 256, 256 }; // The number of bins.
        double[] low = { 0.0D, 0.0D, 0.0D }; // The low value.
        double[] high = { 256.0D, 256.0D, 256.0D }; // The high value.

        // Construct the Histogram object.
        Histogram hist = new Histogram(bins, low, high);

        // Create the parameter block.
        ParameterBlock pb = new ParameterBlock();
        pb.addSource(bufImg); // Specify the source image
        pb.add(null); // No ROI
        pb.add(1); // Sampling
        pb.add(1); // periods

        // Perform the histogram operation.
        PlanarImage output = (PlanarImage) JAI
                .create("histogram", pb, null);

        // Retrieve the histogram data.
        hist = (Histogram) output.getProperty("histogram");

        // Print 3-band histogram.
        int[] mean = new int[] { (int) hist.getMean()[0],
                (int) hist.getMean()[1], (int) hist.getMean()[2] };
        System.out.println("histogram2=" + mean[0] + "," + mean[1] + ","
                + mean[2]);

        return mean;
    }
    public static int[] getMean(BufferedImage srcImg) {

        int h = srcImg.getHeight();
        int w = srcImg.getWidth();

        BufferedImage dstImg = new BufferedImage(w, h,
                BufferedImage.TYPE_INT_RGB);

        double red = 0;
        double green = 0;
        double blue = 0;
        double count = 0.0;
        for (int y = 0; y < h; ++y) {
            for (int x = 0; x < w; ++x) {
                int srcPixel = srcImg.getRGB(x, y);
                // System.out.print(srcPixel);
                int thisRed = new Color(srcPixel).getRed();
                int thisGreen = new Color(srcPixel).getGreen();
                int thisBlue = new Color(srcPixel).getBlue();

                if (thisRed > 0 || thisGreen > 0 || thisBlue > 0) {
                    // tally total colors for 3 components
                    red = red + thisRed;
                    green = green + thisGreen;
                    blue = blue + thisBlue;
                    count++;
                }
            }
        }

        // get averages
        int redAvg = (int) Math.round(red / count);
        int greenAvg = (int) Math.round(green / count);
        int blueAvg = (int) Math.round(blue / count);
        // System.out.println("color mean=" + redAvg + "," + greenAvg + ","
        // + blueAvg + ",count=" + count);
        return new int[] { redAvg, greenAvg, blueAvg };
    }
    public static int[] getMean(ArrayList colorList) {

        double red = 0;
        double green = 0;
        double blue = 0;
        int count = 0;
        for (int i = 0; i < colorList.size(); i++) {
            Color c = (Color) colorList.get(i);
            int thisRed = c.getRed();
            int thisGreen = c.getGreen();
            int thisBlue = c.getBlue();
            // System.out.println(thisRed);
            if (thisRed > 0 || thisGreen > 0 || thisBlue > 0) {
                // tally total colors for 3 components
                red = red + thisRed;
                green = green + thisGreen;
                blue = blue + thisBlue;
                count++;
            }
        }

        int redAvg = (int) (red / count);
        int greenAvg = (int) (green / count);
        int blueAvg = (int) (blue / count);
        // System.out.println("color mean=" + redAvg + "," + greenAvg + ","
        // + blueAvg + ",count=" + count);
        return new int[] { redAvg, greenAvg, blueAvg };
    }
}

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