%!PS-Adobe-2.0
%%Title: Blue Book Program 6, on page 149
%%Creator: Adobe Systems Incorporated 
%%CreationDate: Thu Dec 28 13:20:04 PST 1989
%%EndComments

/concatprocs
	{ /proc2 exch cvlit def
	  /proc1 exch cvlit def
	  
	  /newproc proc1 length proc2 length add array def
	  newproc 0 proc1 putinterval
	  newproc proc1 length proc2 putinterval
	  newproc cvx
	} def

/inch { 72 mul } def
/picstr 3 string def

/imageturkey
	{ 24 23 1 [24 0 0 -23 0 23]
	  { currentfile picstr readhexstring pop }
	  image
	} def

gsave
  3 inch 4 inch translate
  2 inch dup scale
  { 1 exch sub } currenttransfer concatprocs
    settransfer
  imageturkey
  003B00 002700 002480 0E4940
  114920 14B220 3CB650 75FE88
  17FF8C 175F14 1C07E2 3803C4
  703182 F8EDFC B2BBC2 BB6F84
  31BFC2 18EA3C 0E3E00 07FC00
  03F800 1E1800 1FF800

grestore
showpage

% But what does it do?