code: public static InterleavedU8 nv21ToInterleaved( byte[] data , int width , int height ,
  												   InterleavedU8 output ) {
  		if( output == null ) {
  			output = new InterleavedU8(width,height,3);
  		} else {
  			output.reshape(width, height, 3);
  		}
  		if(BoofConcurrency.USE_CONCURRENT ) {
  			ImplConvertNV21_MT.nv21ToInterleaved_U8(data, output);
  		} else {
  			ImplConvertNV21.nv21ToInterleaved_U8(data, output);
  		}
  
  		return output;
  	}
docs: Converts an NV21 image into a {@link InterleavedU8} RGB image.
  
  @param data Input: NV21 image data
  @param width Input: NV21 image width
  @param height Input: NV21 image height
  @param output Output: Optional storage for output image.  Can be null.