docs: public static GrayS16 average( InterleavedS16 input , GrayS16 output ) {
  		if (output == null) {
  			output = new GrayS16(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;
  	}