composite for
visual browsing, and so on. On the other hand, it can't construct a
PostScript file from a GIF.
Some of the constructions are slow and/or require a lot of temporary space.
db_build to handle them. To do this, you must define a
routine (called a checker) to checks whether a format is up to
date (exists and is complete). If it is possible to construct the new
format from some existing format (e.g. create JPEG from TIFF) or to
construct an existing format from the new one (e.g. make GIF from
Microsoft Word.) then you may choose to define one or more (a
transformer) routines. A transformer translates one kind of
format to another.
The routines must be placed in the file
make_formats.pl.
This file has many examples of checkers and transformers,
some simple, some complex.
NCSTRL Documentation