bool ossimImageSourceSequencer::getTileRect(ossim_int64 tile_id, ossimIrect& tileRect) const
{
   // Fetch tile origin for this tile:
   ossimIpt origin;
   bool result = getTileOrigin(tile_id, origin);
   if ( result )
   {
      // Establish the tile rect of interest for this tile:
      tileRect.set_ul (origin);
      tileRect.set_lrx(origin.x + theTileSize.x - 1);
      tileRect.set_lry(origin.y + theTileSize.y - 1);
   }
   return result;
}
void ossimDtedElevationImageSource::computeImageRect(
   const ossimMapProjection* view,
   const ossimGrect& grect,
   ossimIrect& irect) const
{
   if (!view)
   {
      return;
   }
   
   ossimDpt dpt;
   view->worldToLineSample(grect.ul(), dpt);
   irect.set_ul(dpt);
   view->worldToLineSample(grect.lr(), dpt);
   irect.set_lr(dpt);
}