How to use

addOverlays

method

in

net.imagej.display.OverlayService

private void attachOverlays(final ImageDisplay inputDisp,
  final ImageDisplay outputDisp, final List<Overlay> overlays)
{
  final RealRect bounds = overlayService.getSelectionBounds(inputDisp);
  final double[] toOrigin = new double[2];
  toOrigin[0] = -bounds.x;
  toOrigin[1] = -bounds.y;
  final List<Overlay> newOverlays = new ArrayList<>();
  for (final Overlay overlay : overlays) {
    if (overlayWithinBounds(overlay, bounds)) {
      // add a reference to existing overlay?
      if (toOrigin[0] == 0 && toOrigin[1] == 0) {
        newOverlays.add(overlay);
      }
      else { // different origins means must create new overlays
        final Overlay newOverlay = overlay.duplicate();
        newOverlay.move(toOrigin);
        newOverlays.add(newOverlay);
      }
    }
  }
  overlayService.addOverlays(outputDisp, newOverlays);
}

/**
 * Updates the given {@link ImageDisplay} to contain {@link Overlay}s
 * corresponding to all the given {@link ImagePlus}'s Rois (both the active
 * Roi and the Rois stored in ImageJ 1.x's current Overlay).
 */
@Override
public void updateDisplay(final ImageDisplay display, final ImagePlus imp) {
  final List<Overlay> overlaysToRemove = overlayService.getOverlays(display);
  for (final Overlay overlay : overlaysToRemove) {
    overlayService.removeOverlay(display, overlay);
  }
  /*
  if (fullySelected(display, imp)) {
    for (DataView view : display)
      view.setSelected(true);
  }
  else {
  */
  final List<Overlay> overlays = getOverlays(imp);
  overlayService.addOverlays(display, overlays);
  // }
  setModernThreshold(display, imp);
}