code: public void setColorSpace(ColorSpace colorSpace, InterpolationDirection[] dir) {
  		if(dir.length < colorSpace.getNumComponents()) {
  			throw new IllegalArgumentException( "Must specify an interpolation " +
  					"direction for each colorspace component ("+colorSpace.getNumComponents()+")");
  		}
  		this.colorSpace = colorSpace;
  		this.interpolationDirection = dir;
  	}
docs: Sets the ColorSpace to use for interpolation.
  
  The most common scheme for color spaces is to use linear components
  between 0 and 1 (for instance red,green,blue). For such a component, a
  linear interpolation between two colors is used.
  
  Sometimes a component may be in cylindrical coordinates. In this case,
  the component can be mapped in a number of ways. These are set by
  InterpolationDirections.
  
  @param colorSpace The color space for interpolation
  @param interpDirection An array of size colorSpace.getNumComponents()
  giving the interpolation direction for each component.