MPEG: vision, execution, results and a conclusion

Introduction

In 1987, a few months before MPEG was the established, ISO TC 97 Data Processing became the ISO/IEC Joint Technical Committee 1 (JTC 1) on Information Technology. With this operation the data processing industry, renamed information technology industry on the occasion, was able to concentrate on a single Technical Committee (TC) all standardisation activities needed by that industry, including those “electrical”, until then the exclusive purview of IEC.

Thirty-two years later, JTC 1 has become a very large TC, but inside IEC things have been all but static. A major achievement, dating back a couple of decades ago, has been the creation of Technical Committee 100 “Audio, Video and Multimedia systems and equipment”, that grouped activities until then scattered in different parts of IEC.

On the occasion of the IEC General Meeting that included meetings of many IEC TCs, a joint TC 100 and JTC 1 workshop was held in Shanghai on 2019/10/19. MPEG was invited to give a talk about how it develops standards and its most promising current projects. The title selected was an unambiguous “The world is going digital – MPEG did so 30 years ago”.

This article will talk about what I said in the first part of my speech: what drove the establishment of MPEG, how MPEG is organised, and main results produced by MPEG. There is a very short conclusion worth reading.

Digitising the audio-visual distribution

The MPEG story is a successful case of digitisation. Thirty years ago, the audio-visual distribution industry engaged in a process that, unlike what is often happening today, was based on international standards. But why did digitisation of the audio-visual distribution industry succeed? That was because of a number of reasons.

At the end of the 1980s

  • Audio-visual data widely used since a few decades in analogue form
  • Everybody understood that digitising analogue data was technically convenient but costly and that use of compression could reduce the size of digital information and even multiply available capacity
  • Compression technology research was beginning to provide exploitable results
  • Just everybody was waiting for an accessible audio-visual compression technology
    • Telcos: new interactive services and video distribution
    • Broacasters: more efficient distribution of old and new services
    • CE Companies: new products for new distribution channels
    • IT Companies: hardware and software for digital audio-visual distribution services.

At that time standards were needed as they are needed today,. However, at that time, the prevailing attitude of the audio-visual sector was that every industry, country, company etc. should have its own “standard”. The MPEG standardisation way of prevailed over the “old way”. Today  international standards are used to compress audio, moving pictures (including 3D Graphics), and to deliver and consume audio-visual data.

MPEG standards were excellent in terms of quality and standardisation made the audio-visual digitisation technology accessible to all users from a plurality of sources. MPEG’s ability to attract all industry made itthe melting pot of the new global audio-visual distribution that eventually became the famed “industry convergence”.

This is well represented by Figure 1 where the many independent analogue basebands of the analogue worlds, instead of becoming many independent digital basebands, became the single MPEG “digital baseband”.

Figure 1: Audio-visual distribution before and after MPEG

The figure applies specifically to MPEG-2 but it is also the conceptual foundation of the large majority of MPEG standards that followed MPEG-2. The repetition of the first success was made possible by the “MPEG business model”:

  1. When developing a standard MPEG requests companies to provide their best technologies
  2. MPEG develops high-performance standards using the best technologies available at a given time frame
  3. Patents holders receive royalties which they may re-invest in new technologies
  4. When time comes, MPEG can develop a new generation of MPEG standards because it can draw from new technologies, some resulting from patent holders’ re-investments.

In the early MPEG days, the “MPEG industries” were those manufacturing devices (implementation industries) and those actually using the devices for their business (client industries). Both were main contributors to the MPEG standards. Today MPEG is quite different from 30 years ago because the context in which it operates has changed substantially. There is a growing role of companies who ow valuable technologies they contribute to MPEG standards but are unlikely to be manufacturers or users of the standard (technology industries), as depicted in Figure 2.

Figure 2: MPEG standards and industries

The MPEG organisation

What is the inside of the machine that produces the MPEG standards? Judging from Figure 3 one could think that it is a very standard machine.

 Figure 3: The MPEG organisational structure

The Requirements subgroup develops requirements for the standards to be developed; 4 technical subgroups – Systems, Video (that includes two joints groups with ITU-T), Audio and 3D Graphics – develop the standards; the Test subgroup assesses the quality; and the Communication subgroup informs the world of the results.

That’s all? Well, no. One must look first at Table 1 to see the “interaction events” between the different subgroups that took place in the last 12 months during MPEG meetings. They were 68 in total, each lasting from one hour to half a day of joint meetings, each involving at least 2 subgroups and some 3 subgroups or more.

Table 1 MPEG interaction events in 2019

  Systems Video Audio 3DG Test
Requirements 6 14 4 2 1
Systems 11 3 9
Video 1 7 4
Audio 3
3DG 1

Table 1 describes the amount of interaction taking place inside MPEG but does not describe how interaction takes place. In Figure 4 the subgroups are represented as a circle surrounding “units” whose first letter indicates the subgroups they belong to. Units are temporary or stable entities within the subgroups who get together (indicated by the arrows) as orchestrated by the subgroup chairs meeting as “Technical Coordination”.

 

Figure 4: MPEG, subgroups and units

It is this ability to mobilise people with the right expertise that allows MPEG to create standards that can be used to make complete audio-visual systems, but can also be used independently (Figure 5).

Figure 5: MPEG makes integrated standards

MPEG standards are technology heavy. How does MPEG make decisions about which technology get into a standard?

Subgroups are tasked to decide which technologies are adopted in a standard. Because standards are so intertwined, ~10% of official meeting time is used to keep members informed of what is being developed/decided in subgroups, though massive use of IT tools. MPEG members can keep themselves informed of what is being discussed and or decided where and when.

The purpose of MPEG plenaries is to review and approve subgroup decisions. These may be challenged at MPEG plenaries (and this has happened less than 10 times in 30 years). Challenges are addressed by applying thoroughly and conservatively the ISO/IEC definition of consensus.

There is an additional aspect that must be considered: MPEG does not have a constituency because if it had one it would be forced to consider the interests of that industry to the possible detriment of other industries.

Therefore, MPEG has partners, with which it develops standards and customers for which it develops standards. this is shown Table 2.

Table 2 MPEG partners (P) and customers (C)

Committee Status Standards
3GPP C 4, DASH
AES C 2, D
ARIB C 2, 4, H, DASH
ATSC C 2, 4, H, DASH
CTA C Several
DASH-F C DASH
DVB C 2, 4, H, DASH
EBU C Several
IEC TC 100 C 2, 4, H
ISO TC 276 P G
ISO/IEC JTC 1/SC 24 P MAR RF
ITU-T SC 16 P 2, 4, H, I
JPEG C 4, 7, H
Khronos C I
SCTE C Several
SMPTE C Several
TTA C 2, 4, H, DASH
W3C P Several

The success of MPEG standards

So far MPEG has produced ~180 standards. This would amount to an average of 6 standards per years. In practice it is much more because a standard is a living body that typically evolves to include many Amendments and is published multiple times incorporating those Amendments and Corrigenda. Figure 6 show how productive MPEG has been: in spite of being a working group it has produced more standards than any other JTC 1 Subcommittee.

Figure 6: MPEG has published more standards than any other JTC 1 SC

Table 3 lists the 7 areas in which its standards can be classified and maps each area to one of the MPEG standards. It is easy to see that compression and transport are the areas most populated by MPEG standards.

Table 3 MPEG areas and standards

Areas Standard
Compression 1, 2, 4, 5, C, D, G, H, I
Descriptor compression 7
Content e-commerce 21
Combinations of content formats A
Systems & transport 1, 2, 4, B, DASH, H, I, G
Multimedia platforms E, M
Device & application interfaces M, IoMT, U, V

Table 4 assesses the economic value MPEG has brought to the device manufacturing and service industries. The data refer to 2018. Roughly speaking MPEG-enabled devices are worth ~1 trillion USD p.a. and MPEG-enabled services are worth 0.5 trillion USD p.a.

Table 4 The impact of MPEG standards: 1 T$ (devices), 0.5 T$ (services)

Device manufacturing B$ Services B$
Smartphones 522 Pay-TV 227
Tablets 145 TV advertising 177
Laptops 103 Games, films and music 138
TV sets 100 TV production (US) 40
Video surveillance 37 OTT TV 38
Set Top Boxes 20 Social media 34
Digital cameras 18.9 Enterprise video 13.5
In-vehicle infotainment 15 In-flight Entertainment 5
Video conferencing 5 TV subscriptions 1.5
Commercial drones 1.5 SVOD subscriptions 0.5

We should not forget that the life of a large share of the world population is constantly and pervasively affected by MPEG standards.

Conclusions

MPEG is a unique machine that has produced and counts on producing standards affecting the life of billions of people and wide swathes of industry. Industry and consumers have the right to expect that this machine is allowed to do its work and that no improvised apprentice tamper with it.

Posts in this thread

Who “decides” in MPEG?

If MPEG were a typical company, the answer to this question would be simple. Persons in charge of different levels of the organisation “decide”. But MPEG is not a company and there is no chain of command where A tells B to do C or else.

Decisions are made, but how? As an autocracy, an oligarchy or a democracy? To answer these questions, let’s first see how the work in MPEG is organised.

The convenor chairs the 3 plenary sessions.

  1. Monday morning: the results of the ad hoc groups established at the meeting before are presented and the work of the week is organised. The meeting last typically 3 hours. Typically no “decisions” are made.
  2. Wednesday morning: the results of the first two days of work are presented and the work of the rest of the week is organised. Comments and questions for clarification may be asked. Typically the meeting schedule for the next two years is approved, based on the recommendation of a group called “Convenor’s Advisors” who assesses proposals for meeting venues. This can hardly be called a “decision”. The meeting typically lasts 2 hours.
  3. Friday afternoon: the recommendations from subgroups are reviewed by the plenary. Typically they are read, possibly edited and, as a rule, accepted, unless there is a exception I will talk about later. One can say that the plenary “decides”, but actually it ratifies. The meeting typically last 4 hours.

So, where are decisions made?

To answer this question let’s see how the technical work is done in the subgroups: Requirements, Systems, Video (including groups in collaboration with ITU-T), Audio, 3D Graphics and Tests. This is the rough assignment of responsibilities:

  1. Requirements receives proposals for new work, manages the explorations that lead to issuing Calls for Proposals, participates in the assessment of test results and eventually in the definition of profiles. Requirements makes decisions.
  2. Technology development groups – Systems, Video, groups in collaboration with ITU-T, Audio and 3D Graphics – take the results of the test, develop draft specifications and manage the standard approval process (note that tests are not always required to start a new project, but a requirements definition phase is always present). Technology development groups make decisions.
  3. Tests carries out the growing number of tests that are required for the development of visual standards. Tests does not make decisions, it simply provides the results of test to the appropriate group.

It is clear that decisions are really made by subgroups, but how?

The main ingredients of decisions by technology development groups are input contributions by members and their assessment made by the specific subgroup. Evidence must be brought that a technology does what the proponents claims it does and the main tool to achieve this is called “Core Experiment”. This is carried out by the proponent and at least another independent participant.. The results from the two must be compatible and prove that the technology brings gains to be accepted into the standard.

The decisions of the technology development groups are not easy, but getting to a decision can be achieved in a structured way because technology plays an overriding role. Definitely less structured is the process managed by the Requirements group, done just by itself or jointly with a technical group. The decisions to be made are of the type: “does this proposal for new work make sense” or “is this profile needed”?

The question “does this proposal make sense” leaves ample margins for decision because a new technology may be in competition with another existing technology, can be immature, addresses a questionable need etc. MPEG tends to be open to new proposals based on the principle that if someone needs something, why should those unconcerned prohibit the work? After all, the task of MPEG is not to make a “decision” for the new work to start, but only to make a preliminary assessment of a proposal so that a formal proposal for a new work item can be made and voted by National Bodies.

So far, all MPEG proposals for new standards have passed the ISO acceptance criterion of simple majority of P members in the committee approving the proposal.

Adoption of a profile can also be a really tricky matter. Profiles are levels of performance, typically enabled by the presence of technologies in the profiles, required by certain application domains. How much is the profile driven by technology and how much by the market? Discussions may drag on for a long time but eventually a decision must be made. This one is a real decision because the profile becomes part of the standard.

In ISO, to which MPEG belongs, decision must be made by consensus. The ISO definition of consensus is

General agreement, characterized by the absence of sustained opposition to substantial issues by any important part of the concerned interests and by a process that involves seeking to take into account the views of all parties concerned and to reconcile any conflicting arguments.

NOTE    Consensus need not imply unanimity.

Therefore MPEG subgroups make decisions based on this definition of consensus.

What about the exception made at plenaries I was talking about before? It may happen – and probably it did happen less that 10 times in the 30 years of MPEG history – that the party whose wish was overruled by a decision made by a subgroup based on the above definition of consensus, challenges the subgroup consensus at the Friday plenary. The plenary applies the definition of consensus in a very conservatory way to determine if the challenge has to be accepted or the subgroup decision is confirmed.

We can now see that the question “is MPEG an autocracy, an oligarchy or a democracy?” is the wrong question. The right one is the title of this article “who decides in MPEG”. The answer is: MPEG members, if they want to decide. If not the chairs or the convenor have the task of finding a way to a consensus or else declare that no consensus was found. Then, no decision is made.

Posts in this thread

What is the difference between an image and a video frame?

The question looks innocent enough. A video is a sequence of images (called frames) captured and eventually displayed at a given frequency. However, by stopping at a specific frame of the sequence, a single video frame, i.e. an image, is obtained.

If we talk of a sequence of video frames, that would always be true. It would also be true if an image compression algorithm (an “intra-frame” coding system) is applied to each individual frame. Such coding system may not give an exciting compression ratio, but can serve very well the needs of some applications, for instance those requiring the ability to decode an image using just one compressed image. This is the case of Motion JPEG (now largely forgotten) and Motion JPEG 2000 (used for movie distribution and other applications) or some profiles of MPEG video coding standards used for studio or contribution applications.

If the application domain requires more powerful compression algorithms, the design criteria are bound to be different. Interframe video compression that exploits the redundancy between frames must be used. In general, however, if video is compressed using an interframe coding mode, a single frame may very well not be an image because its pixels may have been encoded using pixels of some other frames. This can be seen in the image below dating back 30 years ago in MPEG-1 times.

The first image (I-picture) at the left is compressed using only the pixels in the image. The fourth one (P-picture) is predictively encoded starting from the I-Picture. The second and third image (B-pictures) are interpolated using the first and the fourth. This continue in the next frames where the sequence can be P-B-B-B-P where the last P-picture is predicted from the first P-picture and 3 interpolated pictures (B-pictures) are created from the first and the last P pictures.

All MPEG intraframe coding schemes – MPEG-1, MPEG-2, MPEG-4 Visual and AVC, MPEG-H (HEVC), and MPEG-I (VVC) – have intraframe encoded pictures. This is needed because in broadcasting applications the time it takes for a decoder to “tune-in” must be as short as possible. Having an intra-coded picture, say, every half a second or every second, is a way to achieve that. Having intra-coded pictures is also helpful in interactive applications where the user may wish to jump anywhere in a video.

Therefore, some specific video frames in an interframe coding scheme can be images.

Why don’t we make the algorithms for image coding and intra-coded pictures of an interframe coding scheme the same?

We could but this has never been done for several reasons

  1. The intra-coding mode is a subset of a general interframe video coding scheme. Such schemes are rather complex, over the years many coding tools have been designed and when the intraframe coding mode is designed some tools are used because “they are already there”.
  2. Most applications employing an interframe coding scheme have strict real time decoding requirements. Hence complexity of decoding tools plays a significantly more critical role in an interframe coding scheme than in a still picture coding scheme.
  3. A large number of coding tools in an interframe video coding scheme are focused on motion-related processing.
  4. Due to very large data collected in capturing video than capturing images, the impact of coding efficiency improvement is different.
  5. Real time delivery requirements of coded video have led MPEG to develop significantly different System Layer technologies (e.g. DASH) and make different compromises at the system layer.
  6. Comparisons between the performance of the still picture coding mode of the various interframe coding standards with available image coding standards have not been performed in an environment based on a design of tests agreed among experts from all areas.
  7. There is no proven need or significant benefit of forcing the still picture coding mode of an MPEG scheme to be the same as any image compression standard developed by JPEG or vice-versa.

There is no reason to believe that this conclusion will not be confirmed in future video coding systems. So why are there several image compression schemes that have no relationship with video coding systems? The answer is obvious: the industry that needs compressed images is different than the industry that needs compressed video. The requirements of the two industries are different and, in spite of the commonality of some compression tools, the specification of the image compression schemes and of the video compression schemes turn out to be different and incompatible.

One could say that the needs of traditional 2D image and video are well covered by existing standards, But what about new technologies that enable immersive 2D visual experiences?

One could take a top-down philosophical approach. This is intellectually rewarding but technology is not necessarily progressing following a rational approach. The alternative is to take a bottom-up experiential approach. MPEG has constantly taken the latter approach and, in this particular case, it acts in two directions:

  1. Metadata for Immersive Video (MIV). This representsa dynamic immersive visual experience with 3 streams of data: Texture, Depth and Metadata. Texture information is obtained by suitably projecting the scene on a series of suitably selected planes. Texture and Depth are currently encoded with HEVC.
  2. Point Clouds with a large number of points can efficiently represent immersive visual content. Point clouds are projected on a fixed number of planes and projections can be encoded using any video codec.

Both #1 and #2 coding schemes include the equivalent of video intra-coded pictures. As for video, these are designed using the tools that exist in the equivalent of video inter-coded pictures.

Posts in this thread

MPEG and JPEG are grown up

Introduction

A group of MPEG and JPEG members have developed a proposal seek to leverage the impact MPEG and JPEG standards have had on thousands of companies and billions of people all over the world.

A few numbers related to 2018 tell a long story. At the device level, the installed base of MPEG-enabled devices was worth 2.8 trillion USD and the value of devices in that year was in excess of 1 trillion USD. At the service level, the revenues of the PayTV industry were ~230 billion USD and of the total turnover of the global digital terrestrial television was ~200 billion USD.

Why we need to do something

So far MPEG and JPEG were hosted by Subcommittee 29 (SC 29). The group thinks that it is time to revitalise the 27-year old SC 29 structure. To achieve the goal, let’s make the following considerations:

  1. MPEG has been and continues to be able to conceive strategic visions for new media user experiences, design work plans in response to industry needs, develop standards in close collaboration with client industries, demonstrate their performance and promote their use.
  2. For many years MPEG and JPEG have provided standards to operate and innovate the broadcast, broadband and mobile distribution industries, and the imaging industry, respectively;
  3. MPEG and JPEG have become the reference committee for their industries;
  4. MPEG reference industries’ needs for more standards continue to grow causing a sustained increase in MPEG members attending (currently 600);
  5. JPEG and MPEG have a track record of widely deployed standards developed for and in collaboration with other committees that require a more appropriate level of liaison;
  6. MPEG and JPEG operate as virtual SCs, each with a structure of interacting subgroups covering the required areas of expertise, including a strategic planning function;
  7. MPEG and JPEG have independent and and universally recognised strong brands that must be preserved unfettered and enhanced;
  8. MPEG and JPEG are running standardisation projects whose operation must be guaranteed;

A Strengths-Weaknesses-Opportunities-Threats (SWOT) analysis has been carried out on MPEG. The results point to the need for MPEG

  1. To achieve an SC status compatible with its wide scope of work and large membership (1500 registered members and 600 attending physical meetings)
  2. To retain its scope and structure slightly amended to improve the match of standards with market needs and leverage internal talents
  3. To keep and enhance the MPEG brand.

What should be done

This is the proposal

  1. MPEG becomes a JTC 1 SC (SC 4x) with the title “MPEG compression and delivery of Moving Pictures, Audio and Other Data”;
  2. JPEG becomes SC 29 with the title “JPEG Coding of digital representations of images”;
  3. MPEG/JPEG subgroups become working groups (WG) or advisory groups (AG) of SC 4x/SC 29. MPEG adds a Market needs AG;
  4. Both SC 4x and SC 29 retain existing collaborations with ITU-T and their collaborative stance with other committees/bodies, e.g. by setting up joint working groups (JWG);
  5. SC 4x may create, in addition to genomics, WGs/JWGs for compression of other types of data with relevant committees, building on MPEG’s common tool set;
  6. If selected as secretariat (a proposal for a new SC 4x requires that a National Body be ready to take the secretariat), the Italian National Body (ITNB) is willing to make the following steps to expedite a smooth transition:
    1. Nominate the MPEG convenor as SC 4x chair;
    2. Nominate an “SC 4x chair elect” from a country other than Italy using criteria of 1) con-tinuity of MPEG’s vision and strategy, 2) full understanding of the scope of SC 4x and 3) record of performance in the currently held position;
    3. Call for nominations of convenors of SC 4x working groups (WG). We nominate current subgroup chairs as convenors of the respective WG

The benefits of the proposal

The proposal brings a significant number of benefits

  1. It has a positive impact on the heavy load of MPEG and JPEG work plans:
    1. It supports and enhances MPEG work plan, as MPEG is moved to SC 4x, retaining its proven structure, modus operandi and relationships with client industries in scope;
    2. It supports and enhances JPEG work plan, as SC 29 elevates JPEG SGs to WGs, retaining its proven modus operandi and relationships with client industries in scope;
  2. It preserves and builds upon the established MPEG and JPEG brands;
  3. It retains and improves all features of MPEG success, in particular its structure and modus operandi:
    1. SC 4x holds its meetings collocated with the meetings of its WGs and AGs requesting to meet;
    2. SC 4x facilitates the formation of break-out groups during meetings and of ad hoc groups in between meetings;
    3. SC 4x exploits inter-group synergies by facilitating joint meetings between different WGs and AGs during physical meetings;
    4. SC 4x promotes use of every ICT tools that can improve its effectiveness, e.g. teleconferencing and MPEG-specific IT tools to support standards development.
  4. It enhances MPEG’s and JPEG’s collaboration stance with other committees via Joint Working Groups;
  5. It improves MPEG’s supplier-client relationship with its client industries with its new status;
  6. It adds formal governance to the well-honed MPEG and JPEG structures;
  7. It balances continuity and renewal of MPEG leadership at all levels;
  8. It formalises MPEG’s and JPEG’s high-profile standard reference roles for the video and image sectors, respectively.

The title and scope of SC 4x

Upon approval by JTC 1 and ratification by the TMB, SC 4x will assume the following

  1. Title: MPEG compression and delivery of moving pictures, audio and other data;
  2. Scope: Standardisation in the area of efficient delivery of moving pictures and audio, their descriptions and other data
    • Serve as the focus and proponent for JTC 1’s standardisation program for broadcast, broadband and mobile distribution based on analysis, compression, transport and consumption of digital moving pictures and audio, including conventional and immersive, generated or captured by any technology;
    • Serve as the focus and co-proponent for JTC 1’s standardisation program on efficient storage, processing and delivery of genomic and other data, in agreement and collaboration with the relevant committees.

The SC 4x structure

  1. WG 11 subgroups become:
  2. SC 4x Advisory Groups (AG) – do not produce standards;
  3. SC 4x Working Groups (WG) – produce standards;
  4. Minor adjustments to WG 11 subgroup structure made to strengthen productivity:
  1. New Market needs AG to enhance alignment of standards with market needs (to be installed at an appropriate time after establishment of SC 4x);
  2. Genome Coding moves from a Requirements activity to WG level;
  3. SC 4x retains WG 11’s collaborative stance with other committees/bodies, e.g. Collaborative Teams with ITU-T on Video Coding and Joint Working Groups with ISO/IEC committees to carry out commonly agreed projects;

Joint Working Groups (JWG) may be established if the need for common standards with other ISO/IEC committees is identified.

SC 4x will constantly monitor the state of standards development and adapt its structure accor­dingly, including by establishing new WGs, e.g. on standards for other data types.

SC 4x meetings

  1. For the time being, to effectively pursue its standardisation goals, SC 4x will continue its practice of quarterly meetings collocated with its AGs and WGs (same time/place) organised as an “SC 4x week”, virtually the same of that of MPEG. Extended plenaries are joint meetings of all WGs/AGs. SC 4x plenaries held on the Sunday before and during an hour after the extended plenary on Friday. The last plenary deals with matters such as liaisons, meeting schedules etc that used to be handled by WG 11 plenaries
Day Time Meeting Chaired by
Sunday 14-16 SC 4x plenary Chair
Monday 09-13 Extended SC 4x plenary to review AhG reports and plan for the week Chair elect
Wednesday 09-11 Extended SC 4x plenary to review work done so far by AGs/WGs and plan for the rest of the week Chair elect with Tech. Coord. AG Convenor
Friday 14-17 Extended SC 4x plenary to review and approve recommend­ations produced by AGs/WGs Chair
Friday 17-18 Plenary to act on matters requiring SC 4x intervention Chair
  1. WGs and AGs could have longer meeting durations (i.e. start before first SC 4x meeting);
  2. Carry out a thorough review of all details of meeting sessions, agendas, document regis­tration etc. with the involvement of all affected experts;
  3. Institut Mines Télécom’s unique services offered for the last 15 years would be warmly welcome to preserve and continually improve WG 11’s operating efficiency with the involvement of all WG/AG members.

Title and scope of SC 29

(the following is a first attempt at defining the SC 29 title and scope after creation of SC 4x)

Upon approval by JTC 1, SC 29 will change its title and scope as follows:

  1. Title: JPEG coding of digital representations of images
  2. Scope: Development of international standards for
  • Efficient digital representations, processing and interchange of conventional and immersive images
  • Efficient digital representations of image-related sensory and digital data, such as medical and satellite
  • Support to digital image coding applications
  • Maintenance of ISO/IEC 13522

The structure of SC 29

  1. WG 11 subgroups become:
  1. SC 4x Advisory Groups (AG) – do not produce standards;
  2. SC 4x Working Groups (WG) – produce standards;
  3. SC 29 may set up Joint Working Groups, e.g. with SC 4x and TC 42, to carry out commonly agreed projects;

(the following is a first attempt at defining the SC 29 structure after creation of SC 4x, using the current SG structure of WG 1)

  1. SC 29 meetings: similar organisation as currently done by JPEG.

Why MPEG and JPEG do not work together?

This is a reasonable question, and has a simple answer. They can and should, however, the following should be taken into consideration

In an MPEG moving picture codec, there is always a still picture coding mode, a mode of the general moving picture coding scheme, whose tools are a subset of the tools of the complete moving picture coding scheme.

No need or significant benefit has ever been found that justifies the adoption of a JPEG image coding scheme, as the still picture coding mode of an MPEG moving picture coding scheme. Ditto for other schemes

There is no reason to believe that the same should not apply to such media types as point cloud and lightfield. The still picture coding mode of a dynamic (time dependent) point cloud or lightfield coding scheme uses coding tools from the general coding scheme, not those independently developed for images.

Image compression schemes have their own market. separate from the market of moving picture compression schemes. Often the market for images anticipates the market for moving pictures. That is why independent JPEG standards can be useful.

Posts in this thread