docs: public static void addGaussian(GrayS16 input, Random rand , double sigma , int lowerBound , int upperBound ) {
  
  		for (int y = 0; y < input.height; y++) {
  			int index = input.getStartIndex() + y * input.getStride();
  			for (int x = 0; x < input.width; x++) {
  				int value = (input.data[index] ) + (int)(rand.nextGaussian()*sigma);
  				if( value < lowerBound ) value = lowerBound;
  				if( value > upperBound ) value = upperBound;
  				input.data[index++] = (short) value;
  			}
  		}
  	}