Data Compression Technologies – A FAQ

This post attempts to answer some of the most frequent questions received on the proposed ISO Data Compression Technologies Technical Committee (DCT TC). See here and here. If you have a question drop an email to

Q: What is the difference between MPEG and DCT?

A: Organisation-wise MPEG is a Working Group (WG), reporting to a Subcommittee (SC), reporting to a Technical Committee (TC), reporting to the Technical Management Board (TMB). Another important difference is that a WG makes decision by consensus, i.e. with a high standard of agreement – not necessarily unanimity – while a TC makes decisions by voting.

Content-wise DCT is MPEG with a much wider mandate than media compression involving many more industries than just media.

Q: What is special of DCT to need a Technical Committee?

A: Data compression is already a large industry even if one only looks at the single media industry. By serving more client industries, it will become even larger and more differentiated. Therefore, the data compression industry will require a body with the right attributes of governance and representation. As an example, data compression standards are “abstract” as they are collections of algorithms, and intellectual property intensive (today most patent declarations submitted to ISO are from MPEG). The authority to regulate these matters resides in ISO but the data compression industry will need an authoritative body advocating its needs because the process will only intensify in the future.

Q: Why do you think that a Technical Committee will work better than a Working Group?

A: With its 175 standards produced and its 1400 members, over 500 of which attend quarterly meetings, MPEG – a working group – has demonstrated that it can deliver revolutionising standards affecting a global industry. DCT intends to apply the MPEG successful business model to many other non-homogeneous industries. Working by consensus is technically healthy and intellectually rewarding. Consensus will continue to be the practice of DCT, but policy decisions affecting the global data compression industry often require a vote. Managing a growing membership (on average one member a day joins the group) requires more than an ad hoc organisation like today. The size of MPEG is 20-30 times the normal size of an ISO WG.

Q: Which are the industries that need data compression standards?

According to Forbes, 163 Zettabytes of data, i.e. 163 billion Terabytes, will be produced worldwide in 2025. Compression is required by the growing number of industries that are digitising their processes and need to store, transmit and process huge amounts of data.

The media industry will continue its demands for more compression and for more media. The industries that capture data from the real world with RADAR-like technologies (earth-bound and unmanned aerial vehicles, civil engineering, media etc.), genomics, healthcare (all sorts of data generated by machines sensing humans), automotive (in-vehicle and vehicle-to-vehicle communication, environment sensing etc.), industry 4.0 (data generated, exchanged and processed by machines), geographic information and more.

Q: What are the concrete benefits that DCT is expected to bring?

A: MPEG standards have provided the technical means for the unrelenting growth of the media industry over the last 30 years. This has happened because MPEG standards were 1) timely (i.e. the design is started in anticipation of a need), 2) technically excellent (i.e. MPEG standards are technically the best at a given time), lively (i.e. new features improving the standard are continuously added) and 4) innovative (i.e. a new MPEG standard is available when technology progress enables a significant delta in performance). DCT is expected to do the same for the other industries targeted by DCT.

Q: Why should DCT solutions be better than solutions that are individually developed by industries?

A: “Better” is a multi-faceted word and should be assessed from different angles: 1) technical: compression is an extremely sophisticated domain and MPEG has proved that relying on the best experts produces the best results; 2) ecosystem: implementors are motivated to make products if the market is large and sharing technologies means that implementors face a lower threshold to enter. ON the contrary a small isolated market may not provide enough motivation to implementors; 3) maintenance: an industry may well succeeds in assembling a group of experts to develop a standard. However, a living body like a standard needs constant attention that can no longer be provided if  the experts have left the committee; 4) interoperability: industry-specific data compression methods are dangerous when digital convergence drives data exchange across apparently unrelated industry segments because they create non-communicating islands.


Copyright, troglodytes and digital

We can only guess the feelings of the troglodyte that drew animals on the walls of the Altamira cave, but we have a rough idea of the feelings of the Latin poet Martial towards those who proclaimed his own works as theirs. We know even more precisely the feelings of the Italian 16th century poet Ariosto when he proposed to Duke Alfonso d’Este of Ferrara to share the proceeds that he would obtain from the fines imposed on those who copied the poet’s works.

In now remote analogue times, it was “easy” for the law to prosecute those who made unauthorised copies of a book. The arrival of the photocopier. however, forced the law to put a patch – the so-called photocopy tax. The arrival of the audio cassette made it even easier to make copies of music tracks and so another tax was levied, this time on blank cassettes. The arrival of MP3 made copying audio so easy that the world we knew (I mean, those who knew it), ended there.

The arrival of digital technology was truly a missed opportunity. Instead of solving the problem at the root by exploiting come digital technologies, already widely available at the time, patches were added to patches trying to hold together a situation that had been cracking on all sides for decades.

The last patch in line is the new proposed European copyright directive.

I need to make clear on where I stand. You may well dress up the topic with pompous words like “freedom of the internet”, but it is clear to me that those who make a profit by exposing thousands of snippets of newspaper articles would do well to get in touch first with newspaper publishers. I do not know Martial, but I’m sure Ariosto would have be fully with me on this. So I’m not against a new copyright directive.

I am concerned by the logical foundation of the draft European directive and, in particular, by Article 13. This requires that a filter be placed to check that any digital object uploaded online in the European Union does not violate the copyright of a third party. Instead of saying that uploading somebody else’s content without authorisation should not be done – something I have just said I could not agree more with – Article 13 prescribes a particular solution, i.e. that gateway be placed at a particular place in the value chain.

I happen to have different ideas and I will illustrate them with a personal anecdote. When I was a child and I was free from school, I helped my mother in a market close to our town where she ran a stall. Obviously our main task was to sell, but it was no less important to make sure that the goods on display did not “inadvertently” end up in someone’s pockets. We applied a principle that Martial would have called caveat venditor.

Please note that our attitude of prudence is not the custom of my family alone or of the times of my youth. Over the years I have visited markets in different parts of the world, as a buyer, and I noticed that sellers, regardless of local culture, all behave in the same cautious way.

Back to Article 13, what does this mean in practice? That if I manage a website where my clients upload content, I have the obligation to verify that such content does not violate someone else’s copyright.

But why should I do it? If my mother and I have kept an eye on our goods and millions of sellers on the markets in all latitudes and longitudes pay attention to theirs, why copyright holders should be exempt from the task of controlling their – digital, but who cares -goods?

My mother and I cavimus (bewared), millions of people cavent (beware), the copyright holders caveant (ought to beware).

Some might reply that copyright holders are not able to do that in a global market. That was certainly true before the internet. In the digital age, however, there are technologies that allow copyright holders to control their content without imposing gratuitous burdens on people who are just doing their jobs.

It is very clear to me that technology alone is hardly an answer and that it must be integrated with the law. It is also clear to me that such an integration may not be easy, but it is not a good reason to continue to handle technology as if we were the troglodyte of the Altamira cave.