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RE: CGZ files

From: Weidenbrueck, Dieter <dweidenbrueck@ptc.com>
Date: Mon, 20 Oct 2008 12:50:56 -0400
Message-ID: <1A56AD0206CE2B4788D0A10F7B08FD8F05D063D2@HQ-MAIL4.ptcnet.ptc.com>
To: "Lofton Henderson" <lofton@rockynet.com>, "Bezaire, Benoit" <bbezaire@ptc.com>, "WebCGM WG" <public-webcgm-wg@w3.org>


I agree with your analysis.

One additional question:
Would it make sense to establish cgz as an additional encoding (or
something similar) to make it available to other profiles? I'm not
thinking about WebCGM 1.0 per se, but other profiles building on ISO
8632 might want to use zipping as well.

I guess in general I find it a shame to restrict usage of zipping to
WebCGM 2.1 only, and I would like to find a way to be able to use
compression with any variant of CGM. Probably this could be declared as
a kind of a storage/transportation variant outside of CGM? 

Just thoughts.


-----Original Message-----
From: public-webcgm-wg-request@w3.org
[mailto:public-webcgm-wg-request@w3.org] On Behalf Of Lofton Henderson
Sent: Montag, 20. Oktober 2008 12:06
To: Bezaire, Benoit; WebCGM WG
Subject: RE: CGZ files


Oops, my message crossed with yours.

In short:  I agree that this is a conformance requirement for WebCGM
2.1, specifically that 2.1 viewers must handle gzip-compressed 2.1
instances, and that valid 2.1 instances included plain Binary Encoding
as well as gzip-compressed instances of binary-encoded 2.1 metafiles.

Long analysis:  see my other just-sent message.


At 11:23 AM 10/20/2008 -0400, Bezaire, Benoit wrote:

>I see your point, however...
>We have customers using WebCGM 1.0 "compliant" tools (IsoDraw/IsoView 
>v6 for example). Now, these customers could get a WebCGM 1.0 .cgz and 
>those "compliant" applications would reject them. That's not very 
>Maybe it's better to do this as a WebCGM 2.1 feature.
>-----Original Message-----
>From: Don L. [mailto:dlarson@cgmlarson.com]
>Sent: Friday, October 17, 2008 6:59 PM
>To: Bezaire, Benoit
>Cc: WebCGM WG
>Subject: re: CGZ files
> >  Hi  All,
> >
> >  I find the draft  underspecified about compressed CGM files. More 
> > specifically, we would like to  know what kind of CGM files may be 
> > compressed?
> >
> >  Version1 to  4?
> >  Can I compress a  WebCGM 1.0 CGM file for example?
> >
> >  Is this a WebCGM 2.1  conformance feature for viewer and authoring
> >  Or is this a new WebCGM  2.1 (and only 2.1) 'encoding scheme' ... 
> > for
> > lack  of a better  word?
>I think 'encoding scheme' is a better characterization. The text for 
>this feature in the webcgm 2.1 spec was extracted from the SVG spec.
>My thinking is that this is a viewer conformance issue and a WebCGM 2.1

>viewer should be able to open a file with a .cgz extension and know 
>that it needa to decode this file according to the gzip spec. with the 
>assumption that results will be a file that conforms to the WebCGM 
>profile (any version e.g.
>1.0 , 2.x).
> >  Thanks.
> >  Benoit.
Received on Monday, 20 October 2008 16:55:46 UTC

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