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 imagingbook.common.ij;
010
011import ij.gui.OvalRoi;
012import ij.gui.PointRoi;
013import ij.gui.PolygonRoi;
014import ij.gui.Roi;
015import ij.process.FloatPolygon;
016import imagingbook.common.geometry.basic.Pnt2d;
017
018import java.awt.Polygon;
019
020/**
021 * This class defines static ROI-related utility methods to interface with ImageJ.
022 *
023 * @author WB
024 * @version 2022/09/22
025 */
026public class RoiUtils {
027        
028        private RoiUtils() {}
029
030        /**
031         * Retrieves the outline of the specified ROI as an array of {@link Pnt2d} points with {@code int} coordinates. Note
032         * that unless the ROI is of type {@link PolygonRoi} or {@link PointRoi} only the corner points of the bounding box
033         * are returned. Interpolated contour points are returned for a instance of {@link OvalRoi}.
034         *
035         * @param roi the ROI
036         * @return the ROI's polygon coordinates
037         */
038        public static Pnt2d[] getOutlinePointsInt(Roi roi) {
039                Polygon pgn = roi.getPolygon();
040                Pnt2d[] pts = new Pnt2d[pgn.npoints];
041                for (int i = 0; i < pgn.npoints; i++) {
042                        pts[i] = Pnt2d.PntInt.from(pgn.xpoints[i], pgn.ypoints[i]);
043                }
044                return pts;
045        }
046
047        /**
048         * Retrieves the outline of the specified ROI as an array of {@link Pnt2d} points with {@code double} coordinates.
049         * Returned coordinates are measured relative to the pixel center, e.g., (5.0, 3.0) is assumed to be in the middle
050         * of pixel (5, 3). This method retrieves ROI points with {@link Roi#getFloatPolygon()} but applies type-dependent
051         * correction for consistent point rendering.
052         *
053         * @param roi the {@link Roi}
054         * @return the ROI's outline coordinates
055         */
056        public static Pnt2d[] getOutlinePointsFloat(Roi roi) {
057//              final double offset = (isAreaRoi(roi)) ? -0.5 : 0.0; // replaced by Roi#isLineOrPoint() with IJ 1.53v
058                final double offset = (roi.isLineOrPoint()) ? 0.0 : -0.5; // shift area rois to pixel centers
059                FloatPolygon poly = roi.getFloatPolygon();
060                return getPoints(poly, offset);
061        }
062
063        /**
064         * Extracts the points of an ImageJ {@link FloatPolygon}.
065         *
066         * @param poly the original polygon
067         * @param offset x/y offset to add to coordinates (typically -0.5 for "area ROIs")
068         * @return the polygon's vertex points
069         */
070        public static Pnt2d[] getPoints(FloatPolygon poly, double offset) {
071                Pnt2d[] pts = new Pnt2d[poly.npoints];
072                for (int i = 0; i < poly.npoints; i++) {
073                        pts[i] = Pnt2d.from(poly.xpoints[i] + offset, poly.ypoints[i] + offset);
074                }
075                return pts;
076        }
077
078        /**
079         * Extracts the points of an ImageJ {@link FloatPolygon}. Calls {@link #getPoints(FloatPolygon, double)} with zero
080         * offset.
081         *
082         * @param poly the original polygon
083         * @return the polygon's vertex points
084         */
085        public static Pnt2d[] getPoints(FloatPolygon poly) {
086                return getPoints(poly, 0.0);
087        }
088
089        /**
090         * Converts an array of 2D points (of type {@link Pnt2d}) to a {@link PointRoi} instance.
091         *
092         * @param points v
093         * @return a {@link PointRoi} instance
094         */
095        public static PointRoi toPointRoi(Pnt2d[] points) {
096                PointRoi roi = new PointRoi();
097                for (Pnt2d p : points) {
098                        roi.addPoint(p.getX(), p.getY());
099                }
100                return roi;
101        }
102        
103}