boofcv.gui.ImageHistogramPanel Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of visualize Show documentation
BoofCV is an open source Java library for real-time computer vision and robotics applications.
The newest version!
/*
 * Copyright (c) 2011-2016, Peter Abeles. All Rights Reserved.
 *
 * This file is part of BoofCV (http://boofcv.org).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package boofcv.gui;

import boofcv.struct.image.GrayF32;
import boofcv.struct.image.GrayI;
import boofcv.struct.image.ImageGray;

import javax.swing.*;
import java.awt.*;

/**
 * Draws a histogram of the image's pixel intensity level
 */
public class ImageHistogramPanel extends JPanel {
	protected int totalBins;
	protected double maxValue;
	protected int bins[];

	public ImageHistogramPanel(int totalBins, double maxValue) {
		this.totalBins = totalBins;
		this.maxValue = maxValue;
		this.bins = new int[ totalBins ];
	}

	public void update( ImageGray image ) {

		for( int i = 0; i < bins.length; i++ )
			bins[i] = 0;

		if( image instanceof GrayF32)
			update( (GrayF32)image );
		else if( GrayI.class.isAssignableFrom(image.getClass()) )
			update( (GrayI)image );
		else
			throw new IllegalArgumentException("Image type not yet supported");
	}

	private void update( GrayF32 image ) {
		for( int y = 0; y < image.height; y++ ) {
			for( int x = 0; x < image.width; x++ ) {
				int index = (int)(totalBins*(image.get(x,y)/maxValue));
				if( index >= totalBins || index < 0 )
					System.err.println("Bad index in ImageHistogramPanel");
				else
					bins[index]++;
			}
		}
	}

	private void update( GrayI image ) {
		int max = (int)maxValue;
		for( int y = 0; y < image.height; y++ ) {
			for( int x = 0; x < image.width; x++ ) {
				int index = totalBins*image.unsafe_get(x,y)/max;
				if( index >= totalBins || index < 0 )
					System.err.println("Bad index in ImageHistogramPanel");
				else
					bins[index]++;
			}
		}
	}

	@Override
	public void paintComponent(Graphics g) {
		super.paintComponent(g);

		Graphics2D g2 = (Graphics2D)g;
		g2.setColor(Color.white);
		g2.fillRect(0,0,getWidth(),getHeight());

		int maxCount = 0;
		for( int i = 0; i < totalBins; i++ )  {
			if( bins[i] > maxCount )
				maxCount = bins[i];
		}

		if( maxCount == 0 )
			return;

		g2.setColor(Color.BLACK);

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

		for( int i = 0; i < totalBins; i++ ) {
			int x1 = w*i/totalBins;
			int x2 = w*(i+1)/totalBins;
			int y =  h-h*bins[i]/maxCount;
			g2.fillRect(x1,y,(x2-x1),h-y);
		}
	}
}