code: protected void splitPixels( int indexStart , int indexStop ) {
  		// too short to split
  		if( indexStart+1 >= indexStop )
  			return;
  
  		int indexSplit = selectSplitBetween(indexStart, indexStop);
  
  		if( indexSplit >= 0 ) {
  			splitPixels(indexStart, indexSplit);
  			splits.add(indexSplit);
  			splitPixels(indexSplit, indexStop);
  		}
  	}
docs: Recursively splits pixels.  Used in the initial segmentation.  Only split points between
  the two ends are added