Tomorrow at 4pm there is a programme on Law in Action on Radio 4 in which they examine crown copyright, openstreetmap and the OS. You can listen online.
Its been another high-traffic week on the OSM mailing lists, so lets get ready for a whistle-stop tour to the world of OSM.
The legal debate continues, but the focus has shifted to an attempt to aggregate information about Case Law, Statute Law and general legal questions onto the Legal FAQ wiki page. The principal behind this is firstly to gather together information that we can present to a friendly (and perhaps charitable) copyright lawyer and secondly to get information about similar cases. There are a couple of papers that are definitely worth looking at, this one, written by Dr Charlotte Waelde from the AHRC Research Centre for Studies in Intellectual Property and Technology Law at the University of Edinburgh and this page from the Science Commons website. If reading a journal paper is just too much like hard work, Richard has summarised the main points of the paper here. If direct action is more your thing, some OSM users have been declaring their contributions Public Domain on this wiki page.
If you are new to OSM, Geo and OpenSource projects, there’s probably a lot of things that confuse you. If you are wondering what the difference is between GPX and GPS, head over to the glossary page of the wiki. If there’s a term you want defining, just add it without a definition and someone will update it before too long. There’s also a new mailing list for newbies – sign up here and start asking all those questions that have been bugging you.
There’s been a load of development going on in the OSM commuinty this week. Tom Higgy has written a script that will calibrate OSM image tiles letting you use them with the opensource Treck Buddy navigation software. Take a look at Tom’s work on his site. Next up, Mathew has been working on a new rendering engine that takes OSM data and produces a postscript file, an interesting new take on the rendering issue. The pragmitic developer says; “Maybe there is a use for it, maybe not. I just like hacking PostScript, so this seemed a sensible merge of two enjoyable things…”.
The “Applet” is the editing tool that you use when you click on the “Edit” tab on the OSM website. Its been around since the very beginning of OSM, the first version was written by Steve, the next by Tom Carden, the way support was put in by Imi and inbetween that a few other people have had a hack at it. The Yahoo imagery has prompted a fair bit of development work on the applet. Nick Burch put in some fixes a few weeks ago, and this week Dan Moore has made quite a few bug fixes, including enhanced panning and zooming functions – all of which are now on the live site.
Keith Sharp’s been bussy too, adding a script to extract polygons from the weekly planet dump – useful if you want to extract a particular area of data, rather than load the entire dataset. You can grab a copy here.
My personal “app of the week” is Franciso Santos’ fantastic new Yahoo! imagery plugin for JOSM. Download the plugin from here, then fire up JOSM and get ready for some productive mapping. The plugin works by caching image tiles via Firefox and then loading the image into JOSM – get more info here.
Putney Bridge as seen using the JOSM Yahoo! plugin
The tagging discussions have continued this week too. One problem that’s been identified is that there is currently no way to distinguish a tube station from another type of railway station. Currently we tag railway stations with:
Robert “Jamie” Munro’s not happy though, “that’s just wrong”, he says, and he has a point. After all a railway station is not part of the railway, and so shouldn’t be tagged with “key: railway”. One suggestion is to allow multiple tags with the same key, something like:
Whilst this is supported by XML, it is not currently supported by the OSM API. You can follow discussions about tagging and the OSM ontology here. There are a load of new proposed features that you can vote on this week too- take a look at this wiki page and have your say.
As the amount of data in the OSM database grows, and as the uses of OSM data become more sophisticated and diverse, the underlying data structure will become increasingly important. The idea of “superways” is not a new one, but David Earl has brought the matter to light this week, largely in response to mailing list discussions about tagging motorway junctions. David’s proposal is firstly to introduce the idea of a “superway” as a higher level structure on top of the existing ways, as well as encouraging the API and editors to enforce the existing “rules” of ways (they are contiguous, ordered, unidirectional, non-branching sets of segments). David sees several advantages of the proposed scheme; a road in a housing estate that has numerous branches for example, can be grouped as one object, likewise a complex road junction which is not a single node or a roundabout could also be represented as one object.
Basically all we’re trying to do is assign tags to groups of ways without having to do it to each way, or have an easy method of selecting multiple ways – John McKerrell
There are several strands to this debate, but primarily there is the need to represent real-world objects in the OSM database and however this is done it will involve some level of abstraction. Aled Morris makes a good point that the ability of a renderer to render a particular data-model should not affect the development of that data model. The problem is, that the output of renderers will inevitably affect the way people tag objects and the way people perceive the OSM data model. Nigel Magnay makes the point that whilst you could feasibly tag your way around many situations, this is an inefficient way of dealing with the underlying problem, and what we should be doing modeling the fundamentals properly. Of course different people have different ideas of what the “fundamentals” are and what “properly” is. The herding of cats springs to mind, but then this is all part of OSM’s open, community based way of doing things.
Thats all for this week. With all the new development thats been going on there’s plenty of new toys for every kind of mapper to play with – so get out there (or fire up JOSM) and have some fun.
Dan has a beautiful post on the fantastic new cartography we have rendering.
Oh, my head hurts. I wasn’t around last weekend to do the roundup so Nick agreed to do it. I mailed him suggesting it was a fairly quiet week. “have you been following Legal-talk?” he asked. “Better subscribe. ” I said. Big mistake! It’s not the quantity of mailings that’s the problem, its the passion, quality & general level of understanding. This is where Baz the Blogger’s head really starts to hurt, I’ll keep it brief:
There are three main debates going on at the moment “Is the share-alike road navigable“, “Moving up the stack“, and “The big license debate“. I don’t pretend to do them justice in this one-sentence-per-subject summary so if the subjects interest you and you want to join in, please take a look at the debate. Thanks to David Groom, SteveC, and Tom Chance for starting off these particular threads.
The share-alike road in one sentence is this. Can the license to OSM data be made so that the people that use and enhance OSM data are obliged to make their enhancements available to OSM. To make this concrete, if someone took the OSM data and, for a particular map they placed street names at ‘good’ locations, they would have to return those locations to OSM. There are also other debates on licensing for derivative works. “The big license debate” discusses the pros and cons of CC vs. PD licenses. Should the data be made public domain – a complete free-for-all, or will CC licensing work? One issue with making the data public domain is that everyone that contributed must state that their work is in the public domain. “Moving up the stack” covers whether OSM should just stick to the data layer or move up in some way – afraid this one made my head really hurt!
It is good to see that the FAQ keeps getting updated. For example, people are naturally keen to see the edits and additions they make appear on the slippy map. Now you keen peeps can now go to the FAQ to find how to get your freshly edited area updated quickly… then clear your cache, have a nice relaxing meal & come back to see the results of your hard labours (on a good day ).
Something weird happened with a question by Franciso Santos posted on “Tagging urban streets” – whats the tagging scheme for roads when you get in the centre of a city. Plenty of discussion to agree the scope of the problem, then Mike Collinson proposed something that seemed to be agreed. Wow! Take a look – it doesn’t happen that often.
It seems to have been a busy week for applications. Or should I say nacient application-lets. OJW announced an atlas generation programme. Richard Fairhust announced a test version of Potlatch, a flash-based editor for OSM data and again OJW let us know about an easy way to generate map jpegs on the fly here, surely these should have a CC license logo on them? Or are they derived works – oh, my head is starting to hurt!
Like most (all?) distributed collaborative projects, OSM is discussed at many levels: on the mailing lists (some that we summarise here, legal, talk, dev, party ) the wiki and IRC. There’s only one thing to say about the IRC channel #osm…… “There be sxpert’s”
And finally, you know you’ve got Obsessive Compulsive Open Street Mapping Disorder when “…going to see relatives suddenly sounds interesting…” – too close Dutch! And it just goes on…
By Barry Crabtree
Come along to Pathways of desire, a mapping weekend in south London this weekend. As well as the usual mapping and beer will be mapping of so-called elephant trails – the paths made on open land where no ‘real’ paths exist.
Chris Lightfoot died unexpectedly on 11th February 2007. He is sadly missed by family, friends and colleagues. The funeral was held at St. Bene’t's Church, Cambridge, on 23rd February 2007. Donations, if wished, should be sent to www.no2id.net.
Chris did fantastic work at mysociety and other places and presented at the OS mashup event last October.
The debate surrounding the use and licensing of OSM’s data that was reported in last week’s round-up has continued in earnest this week, resulting in an explosion of traffic on the OSM legal mailing list:
There are several components to the problem. First, there is the issue of copyright. Currently each individual contributor retains the copyright to their contributions. This situation is unlikely to change, as in many countries, such as Germany, it is simply not possible to transfer copyright held by an individual to another body. Next is the issue of the OSM license. All the data held by OSM is licensed under the Creative Commons Attribution-Sharealike 2.0 license (CC-by-SA). CC-by-SA means that anyone can use OSM data for anything they like, provided they give attribution to the creator(s) of the data (the guys with the GPS units and bicycles) and providing that they apply the same license to any derivative works that they make and distribute. I think I speak for the whole OSM community when I say that we all want the best free map of the world we can get; how we define freedom and how we get there is another matter. Richard Fairhurst gives his opinion on some of the problems with the current OSM license:
No webmapping company or cartographer will contribute any data back to OSM except through the goodness of their own heart. That’s because CC-SA doesn’t require you to publish the source code, just the final product.
So if a cartographer produces a beautifully illustrated map using OSM data and then redistributes the map, they are required to redistribute it under the CC-by-SA license. This would make selling the derived work very difficult and Richard and others have suggested that this factor will stop cartographers from using OSM’s data in the future. Instead, they will go to organisations from whom they can buy data under licenses that allow them to create works that they can use commercially, effectively bolstering the position of organisations who sell proprietary data. Frederick Ramm and Robert “Jamie” Munro also point out that this scenario contradicts OSM’s stated aim, to produce maps that are free of the “legal and technical restricions” that most geo-data is subject to.
Take another scenario, one in which a big provider of geo-data gets hold of OSM’s data-set, cleans it, augments it and then uses it to produce map tiles. The current CC-by-SA license does not require this organisation to release the augmented data back into theOSM data set , they would only release their finished product. Those who see this as a problem have suggested making a distinction between the source data (a planet dump for example) and a “rendered” work. It is suggested that the source data could be licensed so that any improvements have to be given back to OSM, whilst derived works would not need to be licensed under such a license, allowing more widespread use of OSM data.
This is a very brief round-up of a pretty complex problem that many people have strong opinions about. Whatever the final outcome of the debate is, it is going to play an important part in shaping the future of OSM. We’ll be meeting with some Creative Commons people in the next couple of weeks, so if you have any ideas about licensing, send a mail to the legal list, or take a look at this wiki page, and make sure your opinion is counted.
Almien published a list of interesting tags, based on the most recent Planet dump. One of my personal favourites is “wrong=oh yes!”, with “description=Official home of the President of The Philippines”, coming a close second. After seeing “blackadder:service=cobler” I know where I will be going to get my shoes fixed in the future, after which I can visit “blackadder:cuisine=fish” for a nice bit of seafood.
OSM@home is a project that uses distributed computing power to render SVG images of places from OSM data. You can browse through the different places here. Through the work of Barry Crabtree, J.D. “Dutch” Schmidt and others, the latest OSM@home client post-processes Osmarender data to produce images with beizer curves, like these:
Free-Map – the countryside oriented open mapping project – now have a similar client that allows people to render Free-Map tiles (with really nice looking SRTM contours) at home. If you want to help out, you can get it from here.
The OSM Cartography meet-up on Saturday saw Artem, SteveC, Steve Chilton and Richard Fairhurst spend a few hours going through the Mapnik config file with the aim of improving the cartography produced by Mapnik. About 10 people met up in Oxford afterwards and there was some interesting discussion about cartography in OSM. Steve Chilton and Richard Fairhurst made the point that a lot of the discussions about rendering OSM data focus on getting as much data as possible onto the maps. They pointed out that the secret of cartography is to represent the information that is needed for a particular use case, and had some convincing examples of traditional cartographic products, like maps oriented towards cyclists, that don’t include many features at all, but succeed in conveying the information needed by the cyclist by choosing the most useful features. This is definitely something for OSM’s renderers to think about. As the database gets larger and more diverse, and the demand for cartographic outputs of OSM data gets greater its going to be increasingly important to carefully select the features that are represented on our maps.
Saturday’s “You know you got OCOSMD (Obsessive Compulsive Open Street Mapping Disorder) when….” thread, started by J.D. “Dutch” Schmidt has thrown up some funny suggestions, along the lines of “…when you read other peoples gpx files as blogs” or “… You forget to pick the girlfriend up from work, but remember the GPS”. It would be so much funnier if it wasnt so painfully true. There’s definitely a fair amount of obsessiveness in the OSM community. I’ve always found that you appreciate things a lot more when you start trying to do or make them for yourself – thats certainly the way its been for me with mapping. Thomas Walraet reported on a French project that’s taking the do-it-yourself ethos to the extreme, making their own GPS circuit boards:
The boards retail for around â‚¬100, with the board’s manurfacturers making no profit. More information is available in French, here.
Thats all for this week, keep tuned to OpenGeoData for all latest news from the world of Open Mapping.
The Bristol mapping party was a week ago now, and we collected some great data:
We were at the Watershed and had about 40 people turn up in all. We almost ran out of GPS units despite the rain, and some good social events happened on Friday, Saturday and Sunday. Laurence and I did an interview you can here here with the local radio station. All in all a good weekend!
Thanks very much to all who helped.