-option "operation" t "Type of operation : \n With another image : 0=add*, 1=multiply, 2=divide,\n 3=max, 4=min, 5=absdiff, 6=squareddiff, 7=difference*, 8=relativ diff\n; For 'scalar' : 0=add*, 1=multiply*, 2=inverse,\n 3=max, 4=min 5=absval 6=squareval\n 7=log 8=exp 9=sqrt 10=EPID 11=divide* 12=normalize (divide by max); \n* operations supported with vector fields as inputs." int default="0" no
+option "operation" t "Type of operation : \n With another image : 0=add*, 1=multiply, 2=divide,\n 3=max, 4=min, 5=absdiff, 6=squareddiff, 7=difference*, 8=relativ diff\n; For 'scalar' : 0=add*, 1=multiply*, 2=inverse,\n 3=max, 4=min 5=absval 6=squareval\n 7=log 8=exp 9=sqrt 10=EPID 11=divide* 12=normalize (divide by max) 13=-ln(I/IO)**; \n* operations supported with vector fields as inputs. \n** for fluence image, if pixel value == 0, consider value=0.5" int default="0" no