Compressing RIB files using DIFF

Presented at the SIGGRAPH 2002, Pixar users group.

During rendering RIB files can consume signifigant amounts of disk space. Though such files are typicallly compressed, additional savings in disk space can be made by considering the inter-frame dependancies. Each RIB file is remarkably similar to its predicessor.

A semi-formal discussing of the approach can be read in this pdf.

To compress sequences of ribs we recomend the "-n" format of diff. In addition to being compact, it can be expanded with virtually no cpu or memory overhead, by a simple C program.

Here are some usefull programs and shell scripts which can perform the operations.

Ian Stephenson.
DCT Systems
NCCA,Bournemouth University