Vol.33 No.4 November 1999
Summer Meeting Produces Results
George S. Carson
This edition of the Standards Pipeline reports on the results of the JTC 1/ SC 24 (Computer Graphics and Image Processing) standards committee meeting held this summer in Korea. This report is divided into several sections:
1. SC 24 as a whole
For more information about the work of SC 24 you can visit the committee’s website.
1. SC 24 (Computer Graphics and Image Processing)
At its summer 1999 meeting, SC 24 reaffirmed its present set of officers:
SC 24 Chairman: George S. Carson, GSC Associates
SC 24’s parent committee, JTC 1 (Joint Technical Committee 1 on Information Technology) passed on to SC 24 a set of work begun by JTC 1’s Imaging and Graphics Business Team (IGBT) (see website). The IGBT, whose purpose was to identify and capture new business for JTC 1, completed its work in January 1999. The IGBT had formed four working groups:
SC 24 decided that the work of one group (Synthetic Environments) was ready to proceed to standardization and that the work of a second group (Archiving and Distribution) was promising enough that it should be pursued further. This work is discussed elsewhere in this report in more detail. SC 24 decided not to continue work in the other two areas (Interaction and Fundamental Objects ) at present due to the lack of sufficient interest.
The subcommittee authorized two projects to proceed to Final Committee Draft (FCD) stage:
SC 24 also made a major decision regarding its future work on profiles (i.e. selection of a subset of features and capabilities of a standard). Recognizing that JTC 1’s concept of International Standardized Profiles as well as the procedural mechanisms developed by JTC 1 for standardizing such profiles were no longer useful for Computer Graphics and Image Processing standards, SC 24 agreed to register future graphics and imaging profiles itself using the International Register of Graphical Items (see website).
SC 24 again affirmed the concept of working in partnership with open industry consortia and other open organizations in the development of future International Standards. The group agreed to continue its long standing cooperative work with the Web 3D Consortium (formerly the VRML Consortium) (see website), with the World Wide Web Consortium (W3C) (see website) and with NATO Air Group IV and the Imagery Standards Management Committee (see website). In addition, SC 24 voted to begin active cooperation with the SEDRIS community (see website) to develop International Standards for data associated with synthetic environments.
2. Synthetic Environments Study Group
SC 24’s Synthetic Environments Study Group met in Korea and recommended to SC 24 that work should proceed to prepare for development of an International Standard in cooperation with the SEDRIS Organization. As part of this work, the study group drafted three documents:
An NP is the first step is ISO standardization. It defines the scope and goals for the proposed work, defines the products and establishes a target schedule for the work.
The Synthetic Environments Study Group was continued with Karen Williams of NIMA as its leader (called the Rapporteur in ISO-speak) until SC 24 approves the NP for the SEDRIS work. At a meeting to be held in Washington D.C. from October 1-5, 1999, it was expected that a new Working Group 8 of SC 24 would be formed to begin in earnest the formal work on a SEDRIS International Standard.
3. Archiving and Distribution Study Group
The Archiving and Distribution Study Group began its work as an IGBT Working Group in January 1999 during the last month of the existence of the IGBT. The work was transitioned to an SC 24 Study Group by JTC 1 at the end of January 1999 and the group met face to face for the first time on June 7, 1999 in conjunction with the SC 24 Plenary and Working Group meetings in Korea. A second meeting is planned for October 1 and 2, 1999 in Alexandria, VA.
The purpose of the Archiving and Distribution Study Group is to address the need for an International Standard(s) or for new or modified profiles of existing standards to better meet the needs of Information Archiving and Distribution. In this regard, the group deals the unique information presentation requirements of electronic libraries, archives and of public access to information, including official records.
SC 24 agreed that the Archiving and Distribution Study Group be continued until the 2000 SC 24 Plenary meeting according to the following terms of reference
4. Interaction Study Group
Following the conclusion of the IGBT’s activities in January 1999, SC 24 agreed to create a Study Group to continue the work that the IGBT WG had started. The Interaction Study Group met on June 8, 1999 in conjunction with the SC 24 Working Groups and Plenary meetings held in Korea. Nine experts attended the meeting, but the Rapporteur, Dr. Paul ten Hagen, was unable to attend the meeting. There was agreement that there is a need for work in advanced interaction, but the feeling of many was that the technologies are still research topics and not yet ready for standardization. At this point the group agreed that except for Reference Models, there was no utility in a separate "interaction standard." Instead, advanced interaction would best be handled in the context of individual standards. Unfortunately, no support seems to be available for developing Reference Model standards at present.
The Interaction Study Group recommended to SC 24 that its work should not be continued unless interest was expressed in continuing the work by September 1, 1999 by at least one SC 24 National Body. Since no such interest was expressed, the work has now been terminated.
5. Working Group 6 (Multimedia Presentation and Interchange)
5.1 3D and the Web
In Korea, Dr. Richard Puk, liaison officer from SC 24 to the Web3D Consortium, reported that the Web3D Consortium continued to be very actively working on the next generation of Web 3D technology while continuing to maintain and update the current Web3D technology standardized as ISO/IEC 14772-1 (VRML 97). Among its many projects, the following ones were reported to be most relevant to International Standardization over the next few months:
The External Authoring Interface (EAI) is a specification to provide access to VRML worlds from external programs. A JTC 1/SC 24 project for this purpose was approved in 1998. Suitable text to serve as an FCD is currently available and SC 24 agreed to ballot it for FCD once it passed the final ballots to become a Web3D.
Dr. Puk reported that Web3D is still trying to decide exactly what to place in an Interoperability enhancements amendment. A project was approved in 1998 at their request for standardizing several diverse "interoperability enhancements" which was originally intended to make support of the two scripting languages mandatory instead of optional and to add the additional nodes developed for MPEG-4. So far, text is available for the former and not yet for the latter. Since then there has been interest in adding some additional features to VRML 97 which increase its ability to interface with data base systems and CAD systems. The data base systems extensions have been defined and implemented and are now a Web3D Recommended Practice. The CAD extensions (actually support for NURBs) have been implemented effectively in at least one commercial browser. There is also interest in adding support for multiple simultaneous textures to support the capabilities now appearing in PC 3D graphics chip sets. All of these are under discussion along with several other possible items.
In addition, there has been talk within the Web3D Consortium of defining several additional profiles to allow more convenient use of VRML for narrow applications such as geometry exchange. This talk is still underway but profiles such as this could be used to more effectively provide interoperability with current graphics applications.
Under the name X3D, the Web3D Consortium is developing a componentized version of VRML 97 with better adaptation to other Web technologies such as DOM and SMIL. This effort is very active and has received much support from the various member companies and the community in general. The goal is to provide VRML compatible functionality which can be loaded on demand and which can utilize resources of the Web for much of its behavior support. The initial approach is to identify a core set of functionality which can then be expanded upon by downloading additional implementation when appropriate. It is expected that the first version of this functionality will have been designed and implemented by the end of the year with prototype demonstrations at SIGGRAPH 99. A follow-on second version would complete the design to support all of current VRML 97 as well as additional capabilities. This would be ready for use as a possible basis for a VRML 2002 revision.
One aspect of the X3D development work is to develop an XML encoding of X3D and/or VRML 97 to better utilize the capabilities in the latest generation of Web browsers. The XML encoding would be in the form of a standardized XML tag set with accompanying DTDs and/or XML schema. To further this work and to ensure input of 3D requirements, the Web3D Consortium has recently joined the World Wide Web Consortium (W3C). In this role, it is participating in the various W3C working groups to ensure that the technical requirements for 3D Internet usage are appropriately addressed.
The Web3D Consortium is also addressing the need for a binary encoding by investigating the viability of using MPEG-4 BIFS for this purpose. The primary stumbling block seems to be IPR concerns arising from the MPEG manner of using proprietary technologies in the MPEG-4 design. This is still under discussion. One difficulty has been the lack of information from SC29 related to exactly what IPR restrictions exist in MPEG-4 and especially for BIFS and what such restrictions mean to the Web3D Consortium should it use BIFS for the binary encoding of VRML 97.
Dr. Puk reported on the Web3D Consortium annual conference (VRML 99) held in Paderborn, Germany, in February. It was well attended even though it was the first time that the conference had been held outside the United States. In fact, it was a demonstration of the success of VRML 97 especially in Europe.
At the VRML 99 Conference, it was learned that Platinum Technologies would be shutting down their 3D development operations throwing the entire, well-respected Cosmo family of VRML products into a state of unknown support. The Web3D Consortium was working with Platinum to arrange for these products to be made available under an open source license policy. This was about to happen when Platinum was itself acquired by another company. At this time, this acquisition has just been consummated but it is too early to determine how this will effect the Cosmo products.
The Web3D Consortium has established an open source infrastructure and currently is distributing Sun’s Java3D VRML browser. This is a useful tool for developing experimental VRML technology and has been used to develop a prototype implementation of the EAI.
5.2 CGM and the Web
During the year since the last SC 24 meeting, significant developments had occurred involving the use of the International Standard Computer Graphics Metafile (ISO/IEC 8632) over the Web. First, The CGM Open Consortium, Inc. (see website) was formed as an organization of vendors and users of CGM technology. This non-profit international consortium has the stated mission of promoting the Computer Graphics Metafile (CGM) as an open and interoperable standard for the exchange of graphical information. Second, working with W3C and SC 24 experts the first profile of CGM for use on the Web, called WebCGM (see website) was developed and adopted as a W3C Recommendation in January 1999 (see website).
To publicize these developments to the graphics community in Asia, an Open Meeting on CGM and the Web was held on June 10, 1999 in conjunction with the SC 24 Working Groups and Plenary meetings held in Korea. Sixteen experts attended the meeting from both SC 24 and from Korean industrial and academic organizations. A tutorial on CGM and one on the Web CGM Profile were presented and demonstrations were convicted that showed four different commercial WebCGM products operating as plug-ins to Internet Explorer 5.0 to view and interact with CGMs conforming to the WebCGM profile.
5.3 Portable Network Graphics (PNG)
The other significant work of SC 24 reported at the Korea meeting was the effort to transpose W3C’s Portable Network Graphics (PNG) Recommendation into an International Standard (see website). This work took longer than anticipated due to both parties agreeing that various clarifications and minor improvements were needed to the original document to raise it to the quality expected of an International Standard. SC 24 scheduled the final editing meeting to produce the PNG FDIS text for October 2 and 3, 1999 in Alexandria, VA.
6. Working Group 7 (Image Processing and Interchange)
WG 7 of SC 24, which had had met in January 1999 in Albuquerque, NM, met again in June 1999 in Korea with the rest of SC 24. The primary work of WG7 — the Image Processing and Interchange Standard (IPI - ISO/IEC 12087) — is now complete and only maintenance and profile work remains. Therefore WG 7 focused its work on defects to Part 2 of IPI, called the Programmer’s Imaging Kernel, or PIKS, and to the finalization and revision of the Part 5 of IPI, called the Basic Image Interchange Format or BIIF.
George S. (Steve) Carson is President of GSC Associates of Las Cruces, NM. He specializes in the development of real-time signal and information processing systems and is the Chairman of ISO/IEC JTC 1/SC 24, Computer Graphics and Image Processing.
George S. Carson
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