Results 1 to 12 of 12

Thread: JPEG issues a draft call for a JPEG reference software

  1. #1
    Member
    Join Date
    Apr 2012
    Location
    Stuttgart
    Posts
    448
    Thanks
    1
    Thanked 101 Times in 61 Posts

    JPEG issues a draft call for a JPEG reference software

    Hi folks and friends of compression,

    the JPEG committee issued a "Draft Call for Proposals" for a JPEG reference software. Strangely, such a software has been missing since ever, and the gap has been filled by third party implementations. The committee considered that there is, by now, some demand for providing a software that illustrates "best practises" for implementation of this standard and is seeking participation from all parties that might be interested in getting their software approved as "official ISO version".

    "Draft" means in particular that this is a document which we will may want to change, in particular to react to comments that hopefully reach us. Thus, if there is any comment made on this, please feel welcome to post here or to contact the parties running the project.

    I'm attaching the draft CfP below, which is the officially approved document.

    To give my personal impressions: I would personally love to see something like libjpegturbo, mozjpeg or Guetzli to fill this gap. At least the Guetzli people hopefully pick it up from here, and I'll try to reach out for additional parties. You may also want to spread the word.

    Greetings,
    Thomas
    Attached Files Attached Files

  2. Thanks (4):

    boxerab (13th April 2017),Cyan (14th April 2017),Jyrki Alakuijala (14th April 2017),Mike (13th April 2017)

  3. #2
    Member
    Join Date
    Jun 2015
    Location
    Switzerland
    Posts
    876
    Thanks
    242
    Thanked 324 Times in 197 Posts
    Quote Originally Posted by thorfdbg View Post
    Hi folks and friends of compression,
    the JPEG committee issued a "Draft Call for Proposals" for a JPEG reference software. Strangely, such a software has been missing since ever, and the gap has been filled by third party implementations. The committee considered that there is, by now, some demand for providing a software that illustrates "best practises" for implementation of this standard and is seeking participation from all parties that might be interested in getting their software approved as "official ISO version".
    This is very interesting!

    Silly questions: what is the benefit of an implementation being an official ISO version? Are there disadvantages? What are the implications on opensource licensing?

    Also, what other software related standards are there where there is a standardized reference software?

  4. #3
    Member
    Join Date
    May 2014
    Location
    Canada
    Posts
    141
    Thanks
    71
    Thanked 21 Times in 12 Posts
    Yes, I had the same question: what is the precise meaning of "royalty free" ? Would software licensed under GPL or AGPL qualify ?
    Under these licenses, distributors are not free to link the software with closed source software. If they wish to do so, they may need to purchase a commercial
    license. Is this licensing model considered "royalty free" ?

  5. #4
    Member
    Join Date
    Apr 2012
    Location
    Stuttgart
    Posts
    448
    Thanks
    1
    Thanked 101 Times in 61 Posts
    Quote Originally Posted by Jyrki Alakuijala View Post
    Silly questions: what is the benefit of an implementation being an official ISO version? Are there disadvantages?
    For a distribution or a company it is probably helpful for marketing purposes to provide the reference - giving a clear indication of their knowledge and background in the field. For - probably less popular - standards, it provides the advantage of providing a point of reference of how to implement it, and what the "best practise" of using the standard actually is. Thus, better market penetration. For example, there is kind some confusion in in a corner case in lossless JPEG that could be made clear to vendors if implemented in software explicitly (we got an explicit request from industry in this respect), and it is also certainly helpful to provide a clear statement even for DCT based JPEG. Some implementations do not write Huffman tables, or quantization tables, and assume that the "standard tables" are then to be used (wrong), others write data that somehow approximate a JPEG codestream, though are still not conforming. It is certainly helpful to provide a reference of "how to do it in practice".
    Quote Originally Posted by Jyrki Alakuijala View Post
    What are the implications on opensource licensing?
    The document is carefully worded in this respect. JPEG has a long tradition of royalty free specifications, but we cannot enforce any particular licensing or IP policy as long as IPs are provided under "RAND conditions" - i.e. "reasonable and non-discriminatory". ISO itself does not even have a software license policy (ECMA has, another story). What we can state is that we - WG1 - as technical experts, would consider it nice if we would end up with a reference software that is available under an open source license. We cannot make any selection based on the license, nor do we want to imply that software has to be provided under a particular license. We're just happy to receive software, and even more so, if the vendor of such a software could open source it for us. The only thing ISO requires is really sufficient rights to publish it along with the standard. That's usually not contradictory to open source.
    Quote Originally Posted by Jyrki Alakuijala View Post
    Also, what other software related standards are there where there is a standardized reference software?
    Funny enough, we provided reference software for every standard thereafter: JPEG-LS has a reference software (albeit only in closed-source binary), JPEG 2000 has three reference software implementations (Jasper, JJ2000, and OpenJPEG) all of which are open source, JPEG XR has one - also open source - and JPEG XT has two (latest count), also both open source. Lately, we seem to stick with BSD as license, though as said, there is no ISO regulation that enforces that. ISO only need to be able to publish it. Strangely, JPEG back then (before my age), never provided a reference software for JPEG (ISO/IEC 10918-1, formally) - a clear failure, if you ask me. What typically happens is that there will be a "10-page" standard document that explains how to compile and run the software, and this "ISO document" will be published along with an electronic attachment consisting of the software. Not much fuzz, but extremely helpful for industry to point at. "Here, this is what JPEG is!" So it's not much work as far as the standard is concerned. It's more work to validate the software, i.e. does it generate "proper" files? Is everything it generates along the lines of the JPEG specification? The "wish list" in the document should give you an indication of what we are looking for and what the priorities are, but these are not set in stone and to discussion - which is why this is a "draft".

  6. Thanks:

    boxerab (16th April 2017)

  7. #5
    Member
    Join Date
    Apr 2012
    Location
    Stuttgart
    Posts
    448
    Thanks
    1
    Thanked 101 Times in 61 Posts
    Quote Originally Posted by boxerab View Post
    Yes, I had the same question: what is the precise meaning of "royalty free" ? Would software licensed under GPL or AGPL qualify ?
    Please see above. We cannot enforce, neither ISO can enforce a particular license. We can just state "ok, we would be happy to receive something in the open source spirit". Thus, if you come up with a software of excellent quality, available under Mozilla license (for example), then that's clearly appropriate.
    Quote Originally Posted by boxerab View Post
    Under these licenses, distributors are not free to link the software with closed source software. If they wish to do so, they may need to purchase a commercial license. Is this licensing model considered "royalty free" ?
    Please see above. My personal thinking is that I would surely not turn down a software if it comes under AGPL conditions and is technically excellent otherwise. Nor would ISO have to say a word against it as long as they can sell it. We would like to put it on www.jpeg.org for everyone to download (along with other reference software implementations we have - of other standards). If you ask me personally about licensing, I would prefer something BSDish, but hey, that's just me, and not a selection criterion. (This being said, the JPEG XT implementations are both under some BSDish license, one of them is in a derived form also available under GPL, though the latter is not officially the reference).

  8. #6
    Member
    Join Date
    Dec 2011
    Location
    Cambridge, UK
    Posts
    506
    Thanks
    187
    Thanked 177 Times in 120 Posts
    Quote Originally Posted by thorfdbg View Post
    My personal thinking is that I would surely not turn down a software if it comes under AGPL conditions and is technically excellent otherwise. Nor would ISO have to say a word against it as long as they can sell it.
    Why would ISO have a need to sell it? Having a reference implementation is extremely useful, but it doesn't need to be anything more than downloadable source and maybe prebuilt library / binaries for ease of comparison.

  9. #7
    Member
    Join Date
    May 2014
    Location
    Canada
    Posts
    141
    Thanks
    71
    Thanked 21 Times in 12 Posts
    Thanks, Thomas, Another related question: can reference software be removed from an ISO standard? You mentioned Jasper and JJ2000 as examples of JPEG 2000 reference software. Both of these projects
    have been abandoned, and probably pose a significant security risk to users.

  10. #8
    Member
    Join Date
    Apr 2012
    Location
    Stuttgart
    Posts
    448
    Thanks
    1
    Thanked 101 Times in 61 Posts
    Quote Originally Posted by JamesB View Post
    Why would ISO have a need to sell it?
    Oh well. There are good ways, and bad ways, and ISO ways. If it's an ISO standard, ISO must be able to sell it along with the standard text. This does not preclude any other form of distribution if the software allows it, and in particular, there is the possibility to opt for a standard that can be downloaded for free from the ISO store (various standards work like this, i.e. you get them for free).
    Quote Originally Posted by JamesB View Post
    Having a reference implementation is extremely useful, but it doesn't need to be anything more than downloadable source and maybe prebuilt library / binaries for ease of comparison.
    As said, there is no problem also offering the same software for download at other places, e.g. www.jpeg.org, if the software license allows that of course. If this is an open source software (as is the goal of the project), then that can be done, of course.

  11. #9
    Member
    Join Date
    Apr 2012
    Location
    Stuttgart
    Posts
    448
    Thanks
    1
    Thanked 101 Times in 61 Posts
    Quote Originally Posted by boxerab View Post
    Thanks, Thomas, Another related question: can reference software be removed from an ISO standard?
    Certainly.
    Quote Originally Posted by boxerab View Post
    You mentioned Jasper and JJ2000 as examples of JPEG 2000 reference software. Both of these projects have been abandoned, and probably pose a significant security risk to users.
    I know. Actually, the plan was to remove both implementations from the JPEG 2000 part 5 specs once OpenJPEG has been published, though it seems that both Antonin (from Intopix) and myself are currently so much involved in the JPEG XS business such that this might still take a while to materialize. I also talked to Antonin on a couple of bugs in OpenJPEG that have been fixed, though the official ISO reference software has not yet been updated, though it should...

  12. #10
    Member
    Join Date
    May 2014
    Location
    Canada
    Posts
    141
    Thanks
    71
    Thanked 21 Times in 12 Posts
    Yes, it would be good to remove those two projects, and not lead users down the wrong path. Who is the editor for the JPEG 2000 reference software, by the way ?

  13. #11
    Member
    Join Date
    Apr 2012
    Location
    Stuttgart
    Posts
    448
    Thanks
    1
    Thanked 101 Times in 61 Posts
    Quote Originally Posted by boxerab View Post
    Who is the editor for the JPEG 2000 reference software, by the way ?
    Editors are assigned per-project, and we currently do not (yet) have a project there. If so, it would probably be called AMD.2 of 15444-5. A natural candidate would be the editor of AMD.1, which would be Antonin Descampe, but as already said, he's pretty busy now.

  14. #12
    Member
    Join Date
    May 2014
    Location
    Canada
    Posts
    141
    Thanks
    71
    Thanked 21 Times in 12 Posts
    Thanks!

Similar Threads

  1. JPEG XT Demo software available on jpeg.org
    By thorfdbg in forum Data Compression
    Replies: 40
    Last Post: 16th September 2015, 15:30
  2. JPEG XT new reference software, online test updated
    By thorfdbg in forum Data Compression
    Replies: 26
    Last Post: 3rd August 2015, 20:27
  3. Replies: 9
    Last Post: 11th June 2015, 23:28
  4. Replies: 0
    Last Post: 6th February 2015, 05:57
  5. JPEG Metadata
    By lorents17 in forum Data Compression
    Replies: 13
    Last Post: 27th April 2014, 21:29

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •