docs: public static GrayU8 threshold( GrayS16 input , GrayU8 output ,
  										int threshold , boolean down )
  	{
  		output = InputSanityCheck.checkDeclare(input,output,GrayU8.class);
  
  		if(BoofConcurrency.USE_CONCURRENT ) {
  			ImplThresholdImageOps_MT.threshold(input, output, threshold, down);
  		} else {
  			ImplThresholdImageOps.threshold(input, output, threshold, down);
  		}
  
  		return output;
  	}