docs: public static GrayU8 average( InterleavedU8 input , GrayU8 output ) {
  		if (output == null) {
  			output = new GrayU8(input.width, input.height);
  		} else {
  			output.reshape(input.width,input.height);
  		}
  
  		if( BoofConcurrency.USE_CONCURRENT ) {
  			ConvertInterleavedToSingle_MT.average(input,output);
  		} else {
  			ConvertInterleavedToSingle.average(input,output);
  		}
  
  		return output;
  	}