%
% stack: pw ph sw sh
%
second 1.0 mul 4 index div
second 1.0 mul 4 index div
%
% stack: pw ph sw sh pw/sw ph/sh
%
2 copy gt
{
%
% width ratio greater than height ratio
% use height ratio to create size of picturebox
%
 pop2nd
}
{
%
% width ratio less than height ratio
% use width ratio to create size of picturebox
%
 pop
} ifelse
dup !ratio
%
% stack: pw ph sw sh ratio
%
5 1 roll pop2
third mul normint
tuck mul normint
exch
%
% stack: fitw fith
%