Subject: Draft statement to Spatial Meeting

From: Steve Carson <[email-masked]>
Date: Tue, 25 Apr 2000 10:29:22 -0600

There is a special JTC 1 meeting on Spatial Standards scheduled for 2-4 May
in Geneva. Over the past few days (April 18 and April 23) some input
documents have been submitted to this meeting that our WG 8 (Environmental
Representation) feels we must respond to if the meeting is to hear the SC
24 and SEDRIS side of the story. 

You can view all the input documents at this web site:

http://www.spatialstandards.org/doi-April2000.htm

We have prepared SC 24 N 2120 whose text is copied into this message and
which is also attached as HTML. We will submit this tomorrow (Wednesday 26
April) assuming no NBs object to its contents. Sorry for the short notice
but we are forced to respond quickly to last minute inputs from TC 211 and
OGC.

- - -

JTC 1/SC 24 N 2120

Statement from JTC 1/SC 24 to the JTC 1 Spatial Meeting in Geneva 2-4 May 2000
SC 24 regrets that its experts in environmental representation will be
unable to attend the second Spatial Meeting to be held in Geneva from 2-4
May 2000. We informed Mr. Martin Ford of the SEDRIS Associates Meeting that
is talking place on those dates in Chicago, Illinois, USA and that our
experts are already committed to attend that meeting.

1 Overlaps in programs of work

As part of its preparatory work for this series of meetings SC 24 experts
have reviewed the program of work of ISO TC 211 and its draft standards. We
call the attention of those attending the second Spatial Meeting (as well
as JTC 1 and TC 211 in general) to the fact that several items in the TC
211 program of work significantly overlap the scope of JTC 1/SC 24.  Drafts
of these TC 211 standards reviewed by SC 24 experts at present conflict
with many published International Standards. Four specific examples of such
overlap with identified opportunities for synergistic collaboration follow:

1.1 ISO/PDTR 16569.2, Geographic information - Imagery and gridded data ,
TC 211 N 752

There is an opportunity for this standard to be developed as a profile of
ISO/IEC 12087 Basic Image Interchange Format (BIIF). SC 24 has long
standing and widely recognized expertise in image processing (to include
what is often called gridded data) and image interchange formats.

1.2 ISO/CD 19104.2, Geographic information - Terminology , TC 211 N 816

This draft standard gives different and incompatible definitions to many
terms that have established definitions in published International
Standards developed by SC 24. A few examples are: digital image, image,
edge, event, face, feature, node, polygon, primitive, geometric primitive,
surface patch, texture and transformation.

1.3 ISO/CD 19117.3, Geographic information - Portrayal , TC 211 N 828

There is an opportunity to base this standard on profiles of one or more of
SC 24's published International Standards. Candidates include:
Computer Graphics Metafile (CGM) ISO/IEC 8632
Virtual Reality Modeling Language (VRML) ISO/IEC 14772 (to include the
recently developed GeoVRML extension.)
Portable Network Graphics (PNG) FDIS 15948
other SC 24 standards such as GKS (ISO 7942), PHIGS (ISO/IEC 9592) and CGI
(ISO 9636)
Several of the above SC 24 standards (CGM, VRML, PNG) are already used in
commercial practice to portray geographic information. Examples were
demonstrated by SC 24 experts at the first Spatial Meeting in Menlo Park,
California, USA in February 2000.

1.4 ISO/CD 19107, Geographic information - Spatial schema , TC 211 N 818

The definitions and concepts in this draft standard conflict with
established definitions in published International Standards developed by
SC 24. Some of these concepts and definitions are point, face, edge,
primitive, curve, solid, surface, spline, surface patch, conics, and
polygonal surface. These and similar concepts are developed and defined in
SC 24 standards that include PHIGS (ISO/IEC 9592), VRML (ISO/IEC 14772) and
CGM (ISO/IEC 8632). There is a substantial opportunity for synergistic
collaboration if TC 211 were to base this standard on the published work of
SC 24 rather than creating conflicting new concepts.

SC 24 believes that since so much of the work of TC 211 overlaps that of SC
24 that substantial opportunities exist for collaborative work and
exploitation of standards developed by SC 24 in the work of TC 211. Such
collaboration is expected to have a synergistic effect that will benefit
both organizations.

2 Summary

SC 24 notes that overlaps in areas of work are inevitable when one
committee such as JTC 1 has the scope "Information technology" and then new
committees are formed to address Information Technology for specific
application areas such as TC 204 (Transport information and control
systems), TC 211 (Geographic information/geomatics), and TC 215 (Health
informatics).  Rather that reacting to such overlaps negatively, SC 24
chooses to view them as opportunities for synergistic collaboration. 

In this spirit of cooperation SC 24 notes that its own work in process in
transposing SEDRIS and related technologies into International Standards
(ISO WDs 18023 - 18026) can benefit from properly referencing applicable TC
211 work.  The Modeling and Simulation market that our standards address is
a natural consumer of geographic information which forms an important basis
for the Synthetic Environments that are the subject of our work.  We have
requested the assistance of TC 211 in assuring the highest possible degree
of compatibility and interworking among our respective standards.

Steve Carson
Chair, ISO/IEC JTC 1/SC 24
Computer Graphics and Image Processing
---------------------------------------------------------
Steve Carson       http://www.huntel.com/~carson/
GSC Associates     http://www.gscassociates.com/
5272 Redman Road   phone:+1-505-521-7399; fax:+1-505-521-9321
Las Cruces, NM 88011 USA     e-mail:  [email-masked]
---------------------------------------------------------