[XeTeX] How does xetex handle non-native imagefilessuchas eps?

[Yuan Qi]

Ulrike Fischer <news2 at ...> writes:

> Ah, I understand. No this command can't be used to avoid a bb-file or
> something like that. The command is inserted in the \special and it an
> instruction for the driver (xdvidpfmx). It will be executed to late. 

Basically, there is no way for xetex to execute a program before compilation and
the dvipdfmx.cfg image handler setting is only intended for eps files, right?