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 Ch03_Point_Operations;
010
011import ij.ImagePlus;
012import ij.gui.GenericDialog;
013import ij.plugin.filter.PlugInFilter;
014import ij.process.ImageProcessor;
015import imagingbook.common.ij.DialogUtils;
016import imagingbook.core.jdoc.JavaDocHelp;
017import imagingbook.sampleimages.GeneralSampleImage;
018
019import static imagingbook.common.ij.IjUtils.noCurrentImage;
020
021/**
022 * <p>
023 * This ImageJ plugin does the same as the {@link Raise_Contrast} plugin but uses the one-dimensional pixel array to
024 * read and writes pixel values without calling any intermediate access methods, which is obviously more efficient. See
025 * Sec. 3.1.1 of [1] for additional details.
026 * </p>
027 * <p>
028 * [1] W. Burger, M.J. Burge, <em>Digital Image Processing &ndash; An Algorithmic Introduction</em>, 3rd ed, Springer
029 * (2022).
030 * </p>
031 *
032 * @author WB
033 * @see Raise_Contrast
034 */
035public class Raise_Contrast_Fast implements PlugInFilter, JavaDocHelp {
036        
037        /** Contrast scale factor. */
038        public static double S = 1.5;
039
040        /** Constructor, asks to open a predefined sample image if no other image is currently open. */
041        public Raise_Contrast_Fast() {
042                if (noCurrentImage()) {
043                        DialogUtils.askForSampleImage(GeneralSampleImage.IrishManor);
044                }
045        }
046
047        @Override
048        public int setup(String arg, ImagePlus im) {
049                return DOES_8G;
050        }
051        
052        @Override
053        public void run(ImageProcessor ip) {
054                if (!runDialog()) {
055                        return;
056                }
057
058                // ip is assumed to be of type ByteProcessor
059                byte[] pixels = (byte[]) ip.getPixels();
060                for (int i = 0; i < pixels.length; i++) {
061                        int a = 0xFF & pixels[i];
062                        int b = (int) (a * S + 0.5);
063                        if (b > 255)
064                                b = 255;
065                        pixels[i] = (byte) (0xFF & b);
066                }
067        }
068
069        private boolean runDialog() {
070                GenericDialog gd = new GenericDialog(this.getClass().getSimpleName());
071                gd.addHelp(getJavaDocUrl());
072                gd.addNumericField("Contrast scale (S > 0)", S, 2);
073
074                gd.showDialog();
075                if(gd.wasCanceled())
076                        return false;
077
078                S = gd.getNextNumber();
079                return true;
080        }
081}