void interpolate() {
   Roi roi = imp.getRoi();
   if (roi == null) {
     noRoi("Interpolate");
     return;
   }
   if (roi.getType() == Roi.POINT) return;
   if (IJ.isMacro() && Macro.getOptions() == null) Macro.setOptions("interval=1");
   GenericDialog gd = new GenericDialog("Interpolate");
   gd.addNumericField("Interval:", 1.0, 1, 4, "pixel");
   gd.addCheckbox("Smooth", IJ.isMacro() ? false : smooth);
   gd.showDialog();
   if (gd.wasCanceled()) return;
   double interval = gd.getNextNumber();
   smooth = gd.getNextBoolean();
   Undo.setup(Undo.ROI, imp);
   FloatPolygon poly = roi.getInterpolatedPolygon(interval, smooth);
   int t = roi.getType();
   int type = roi.isLine() ? Roi.FREELINE : Roi.FREEROI;
   if (t == Roi.POLYGON && interval > 1.0) type = Roi.POLYGON;
   if ((t == Roi.RECTANGLE || t == Roi.OVAL || t == Roi.FREEROI) && interval >= 5.0)
     type = Roi.POLYGON;
   if ((t == Roi.LINE || t == Roi.FREELINE) && interval >= 5.0) type = Roi.POLYLINE;
   if (t == Roi.POLYLINE && interval >= 1.0) type = Roi.POLYLINE;
   ImageCanvas ic = imp.getCanvas();
   if (poly.npoints <= 150 && ic != null && ic.getMagnification() >= 12.0)
     type = roi.isLine() ? Roi.POLYLINE : Roi.POLYGON;
   Roi p = new PolygonRoi(poly, type);
   if (roi.getStroke() != null) p.setStrokeWidth(roi.getStrokeWidth());
   p.setStrokeColor(roi.getStrokeColor());
   p.setName(roi.getName());
   transferProperties(roi, p);
   imp.setRoi(p);
 }
  void addImage() {
    ImagePlus imp = IJ.getImage();
    int[] wList = WindowManager.getIDList();
    if (wList == null || wList.length < 2) {
      IJ.error("Add Image...", "The command requires at least two open images.");
      return;
    }
    String[] titles = new String[wList.length];
    for (int i = 0; i < wList.length; i++) {
      ImagePlus imp2 = WindowManager.getImage(wList[i]);
      titles[i] = imp2 != null ? imp2.getTitle() : "";
    }
    int x = 0, y = 0;
    Roi roi = imp.getRoi();
    if (roi != null && roi.isArea()) {
      Rectangle r = roi.getBounds();
      x = r.x;
      y = r.y;
    }
    int index = 0;
    if (wList.length == 2) {
      ImagePlus i1 = WindowManager.getImage(wList[0]);
      ImagePlus i2 = WindowManager.getImage(wList[1]);
      if (i2.getWidth() < i1.getWidth() && i2.getHeight() < i1.getHeight()) index = 1;
    } else if (imp.getID() == wList[0]) index = 1;

    GenericDialog gd = new GenericDialog("Add Image...");
    gd.addChoice("Image to add:", titles, titles[index]);
    gd.addNumericField("X location:", x, 0);
    gd.addNumericField("Y location:", y, 0);
    gd.addNumericField("Opacity (0-100%):", 100, 0);
    gd.addCheckbox("Create image selection", createImageRoi);
    gd.showDialog();
    if (gd.wasCanceled()) return;
    index = gd.getNextChoiceIndex();
    x = (int) gd.getNextNumber();
    y = (int) gd.getNextNumber();
    double opacity = gd.getNextNumber() / 100.0;
    createImageRoi = gd.getNextBoolean();
    ImagePlus overlay = WindowManager.getImage(wList[index]);
    if (wList.length == 2) {
      ImagePlus i1 = WindowManager.getImage(wList[0]);
      ImagePlus i2 = WindowManager.getImage(wList[1]);
      if (i2.getWidth() < i1.getWidth() && i2.getHeight() < i1.getHeight()) {
        imp = i1;
        overlay = i2;
      }
    }
    if (overlay == imp) {
      IJ.error(
          "Add Image...", "Image to be added cannot be the same as\n\"" + imp.getTitle() + "\".");
      return;
    }
    if (overlay.getWidth() > imp.getWidth() && overlay.getHeight() > imp.getHeight()) {
      IJ.error(
          "Add Image...", "Image to be added cannnot be larger than\n\"" + imp.getTitle() + "\".");
      return;
    }
    if (createImageRoi && x == 0 && y == 0) {
      x = imp.getWidth() / 2 - overlay.getWidth() / 2;
      y = imp.getHeight() / 2 - overlay.getHeight() / 2;
    }
    roi = new ImageRoi(x, y, overlay.getProcessor());
    roi.setName(overlay.getShortTitle());
    if (opacity != 1.0) ((ImageRoi) roi).setOpacity(opacity);
    if (createImageRoi) imp.setRoi(roi);
    else {
      Overlay overlayList = imp.getOverlay();
      if (overlayList == null) overlayList = new Overlay();
      overlayList.add(roi);
      imp.setOverlay(overlayList);
      overlay2 = overlayList;
      Undo.setup(Undo.OVERLAY_ADDITION, imp);
    }
  }