Synopsis
		sfsaltpepper < in.rsf > out.rsf den=10. inten=0.1 rep=n allpos=n noise=n seed=time(NULL)

Parameters
		bool allpos=n [y/n] if y, assume positive noise   float den=10. noise density (percent, default=10, Min=0, Max=100)   float inten=0.1 noise intensity (multiple peak value of data, default=0.1)   bool noise=n [y/n] if y, output noise only   bool rep=n [y/n] if y, replace data with noise   int seed=time(NULL) random seed