001/*******************************************************************************
002 * This software is provided as a supplement to the authors' textbooks on digital
003 * image processing published by Springer-Verlag in various languages and editions.
004 * Permission to use and distribute this software is granted under the BSD 2-Clause
005 * "Simplified" License (see http://opensource.org/licenses/BSD-2-Clause).
006 * Copyright (c) 2006-2023 Wilhelm Burger, Mark J. Burge. All rights reserved.
007 * Visit https://imagingbook.com for additional details.
008 ******************************************************************************/
009package Ch09_Automatic_Thresholding;
010
011import ij.IJ;
012import ij.ImagePlus;
013import ij.plugin.filter.PlugInFilter;
014import ij.process.ByteProcessor;
015import ij.process.ImageProcessor;
016import imagingbook.common.threshold.global.GlobalThresholder;
017import imagingbook.common.threshold.global.MaxEntropyThresholder;
018import imagingbook.core.jdoc.JavaDocHelp;
019import imagingbook.sampleimages.GeneralSampleImage;
020
021import static imagingbook.common.ij.DialogUtils.askForSampleImage;
022import static imagingbook.common.ij.IjUtils.noCurrentImage;
023import static java.lang.Float.isFinite;
024
025/**
026 * <p>
027 * ImageJ plugin demonstrating the use of the {@link MaxEntropyThresholder} class.
028 * See Sec. 9.1.5 of [1] for additional details.
029 * </p>
030 * <p>
031 * [1] W. Burger, M.J. Burge, <em>Digital Image Processing &ndash; An Algorithmic Introduction</em>, 
032 * 3rd ed, Springer (2022).
033 * </p>
034 * 
035 * @author WB
036 * @version 2022/04/02
037 * @see imagingbook.common.threshold.global.MaxEntropyThresholder
038 */
039public class Global_MaxEntropy implements PlugInFilter, JavaDocHelp {
040        
041        /**
042         * Constructor, asks to open a predefined sample image if no other image
043         * is currently open.
044         */
045        public Global_MaxEntropy() {
046                if (noCurrentImage()) {
047                        askForSampleImage(GeneralSampleImage.Kepler);
048                }
049        }
050        
051        @Override
052        public int setup(String arg, ImagePlus imp) {
053                return DOES_8G;
054        }
055        
056        @Override
057        public void run(ImageProcessor ip) {
058                ByteProcessor bp = (ByteProcessor) ip;
059                
060                GlobalThresholder thr = new MaxEntropyThresholder();
061                float q = thr.getThreshold(bp);
062
063                if (isFinite(q)) {
064                        bp.threshold(Math.round(q));
065                }
066                else {
067                        IJ.showMessage("no threshold found");
068                }
069        }
070}