The -s1 and -s2 flags select the style of UPC to generate. The default, -s1, looks more or less like this:
|||||||||||||||| |||||||||||||||| |||||||||||||||| |||||||||||||||| 0||12345||67890||5The other style, -s2, puts the product type digit higher up, and doesn't display the checksum digit:
|||||||||||||||| |||||||||||||||| 0|||||||||||||||| |||||||||||||||| ||12345||67890||
As presently configured, pbmupc produces a bitmap 230 bits wide and 175 bits high. The size can be altered by changing the defines at the beginning of the program, or by running the output through pnmenlarge or ppmscale.
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