RE: [cgmo-webcgm] CGM Compression Use Case

["Bezaire, Benoit" <bbezaire@ptc.com>]

Hi Don,

Interesting data! Can we assume that the file contains mainly polylines?
No raster images I presume if you get 80-94% compression ratio?

Benoit. 

-----Original Message-----
From: Don Larson [mailto:dlarson@cgmlarson.com] 
Sent: Monday, August 20, 2007 3:31 PM
To: cgmo-webcgm@lists.oasis-open.org
Subject: [cgmo-webcgm] CGM Compression Use Case

All,

Use case for "Z Compression of CGM Files":

In an oil field application, very large CGM are transmitted via Internet
several times a day from drilling locations to centrally located
engineers for analysis.  Each CGM file ranges in size from 2 to 10 Mb.
In a typical work week, an engineer may receive and archive as many as
100 files.
This equates to  600 Mb of CGM data a week which over the life of just
one drilling project an engineer may accumulate several giga-bytes of
CGM data on his laptop. 

Analysis of a typical set of CGM files determined that reduction in file
size ranged form 80 to as much as 94% reduction in file size with Z
compression.

It would save a significant amount of bandwidth and storage space if the
CGM file could be Z compressed before transmission and then decompressed
on the fly by the viewer as they being interpreted for viewing.

Regards,
Don Larson
Larson CGM Software
(713)977-4177 x102
www.cgmlarson.com