svoid g22_highlightRegion(int[] pixels, ImageSurface is, Gazelle22_ImageToRegions itr,
  Pt mouse default is.mousePosition, bool showRegionsAsOutline) {
  if (mouse != null && itr != null && itr.regions != null) {
    var regions = itr.regions;
    int iHighlightedRegion = regions.regionAt(mouse);
    int color = 0xFF00C000;

    if (showRegionsAsOutline) {
      RegionBorder_innerPoints x = new(regions, iHighlightedRegion);
      gazelle22_highlightRegionOutline(pixels, itr, x);
    } else
      regions.markRegionInPixelArray(pixels, iHighlightedRegion, color);
  }
}