code: public void setScaleFactors( int ...scaleFactors ) {
  		for( int i = 1; i < scaleFactors.length; i++ ){
  			if( scaleFactors[i] % scaleFactors[i-1] != 0 ) {
  				throw new IllegalArgumentException("Layer "+i+" is not evenly divisible by its lower layer.");
  			}
  		}
  
  		// set width/height to zero to force the image to be redeclared
  		bottomWidth = bottomHeight = 0;
  		this.scale = scaleFactors.clone();
  		checkScales();
  	}
docs: Specifies the pyramid's structure.  Scale factors are in relative to the input image.
  
  @param scaleFactors Change in scale factor for each layer in the pyramid.