Synopsis
		sfprep4plot inp= out= verb=n h=768 w=1024 h= w= unit=px ppi= prar=y

Only one of the h and w parameters needs to be specified.
If prar=n, no action will be taken on axis for which h/w was not specified
If prar=y and only one par (h or w) is specified, the picture will scale
along both axes until it is of the specified dimension.

Parameters
		string h=   string inp= input file   string out= output file   int ppi= outp. resolution (px/in). Necessary when unit!=px   bool prar=y [y/n] if y, PReserve Aspect Ratio of input   string unit=px unit of h and w. Can be: px, mm, cm, in   bool verb=n [y/n] if y, print system commands, outputs   string w=