Description:

This is a sub-module to PDF::Reuse. It creates barcode "images" to be used in
PDF documents. It uses GD::Barcode and its sub-modules: GD::Barcode::Code39,
COOP2of5, EAN13 and so on, to calculate the barcode pattern. For Code128 it uses
Barcode::Code128.

Normally the barcodes are displayed on a white background and with the characters
under the bars. You can rotate the "image", make it smaller or bigger, prolong the
bars and change the background.
(But then, don't forget to test that your barcode scanner still understands it.)

If you don't change the size of the "image", the bars are approximately 24 pixels
high (the guard bars a few pixels longer) and the box/background is 38 pixels high
and something like 20 pixels wider than the barcodes. The text under the bars are
10 pixels high.

The barcodes are generated using a Type3 font by default. Ghostscript and xpdf
don'thave support for Type3 fonts. If you want to target engines that don't
handle Type3 fonts properly, see the "mode" parameter.