byte[][] getOverlay(ImagePlus imp) {
if (imp.getHideOverlay())
return null;
Overlay overlay = imp.getOverlay();
if (overlay==null) {
ImageCanvas ic = imp.getCanvas();
if (ic==null) return null;
overlay = ic.getShowAllList(); // ROI Manager "Show All" list
if (overlay==null) return null;
}
int n = overlay.size();
if (n==0) return null;
if (Orthogonal_Views.isOrthoViewsImage(imp))