OpenStreetMap
In December of 2021 a bi-annual International Cartographic Conference was held in Florence, Italy.
Because of Covid it was a mixed conference, however ~200 people (my estimation, I do not have an official number) have attended on site (with many more participating on-line).
OpenStreetMap was mentioned a lot. This is a good thing, but… the only good thing. It was always mentioned just as a data source. And it seems everybody is taking for granted that OSM data while being heterogenic in saturation is at least in schema (tagging) a consistent thing and slowly smartly evolving, rather than eroding. Nobody new or even expected that schema in OSM can be changed by anybody, even people who have absolutely no clue in Cartography/GIS. And this is not only a possibility, but a reality.
ICC is held by International Cartographic Association (https://icaci.org/) - main worldwide body of professional Cartographers. It has a lot of commissions for different aspects of cartography: map design, atlases, map production, military mapping, generalisation and multiple-representation, maps for people with disabilities etc. etc. And still OpenStreetMap was NOT mentioned for cartography in ANY presentation in any of the directions at all (well, one presenter said “OSM is getting better”).
Why is that? Well it is because OpenStreetMap (community) is not only doing nothing in cartography front, but the whole fabric of OSM is made in a way that anybody trying to do some quality/cartography work is quickly pushed away and whole thing is rampaged by several clueless people running and destroying whatever value is still left in OSM (because there are no means to stop them).
Sad, but without change in governance there will be no change at all.
Discussion
Comment from SomeoneElse on 4 January 2022 at 17:48
If you believe that there is a problem with the direction that OSMF is going in, perhaps you should consider standing in the board elections in 2022 suggesting a different direction?
I suspect that if you want people to vote for you you you might want to not describe some other people in the OSM community as “clueless people” though; I’d suggest trying to understand why they hold views that are different to yours and see things from their point of view, as well as articulating your own views.
Comment from Tomas Straupis on 4 January 2022 at 18:52
I did not call OSM community as “clueless people” because I do not think so, quite the opposite is true. There is a very small number of clueless people who unfortunately have a lot of spare time. But the problem is not those people (they do believe they are doing something good). The actual problem is the absolute lack of QA measures/guidelines on this level.
And I do not see OSMF as having any legitimacy or mandate to change anything in this regard…
Comment from FourOh on 4 January 2022 at 19:11
I am brand new, I registered today. Most everything I do online is to find inspiration, direction, resources to build a local 3D printing community, and grow it into a manufacturing and relevant supply-chain and talent pool association (again, local). I am indeed clueless, I never in my life trained in cartography or anything relevant - and whats better or worse I look at everything regarding how it could help me in my limited scope.
I do not want to get in trouble by using Google data, OMS is pretty awesome to provide the basis, and let me create a map of all the current industrial, warehousing, office building capacity. I only going to update the map where I live and work.
So maybe, if “purposing” OMS, promoting to be “purposed” that could help. Like people who “want to learn Linux” I always tell them find something to do with it.. then its going to be easier, than just “learning it”. I always tell them to “purpose it”.
Comment from Eiim on 5 January 2022 at 04:28
I’ll admit that I am far from a professional cartographer at this point, but I’m a little confused by what seem to me to be the contradictory statements of “OpenStreetMap was mentioned a lot” and “OpenStreetMap was NOT mentioned for cartography in ANY presentation in any of the directions at all (well, one presenter said “OSM is getting better”).” In what way was OSM mentioned in this cartography conference, if not for cartography? I’m guessing you’re referring to it being “mentioned just as a data source”? To me, data sources seem to be a very important aspect of cartography; if the underlying data is bad, the aesthetics of the map are more or less irrelevant. Are you saying that you wished that there was more discussion of the cartographic aspects of Carto or other OSM renderers?
Comment from Tomas Straupis on 5 January 2022 at 07:31
Yes, OSM was only mentioned as a data source and mostly with expectations of data quality which are much higher than OSM data really is. You’re right, data quality is essential, but with current problematic lack of QA control OSM data is not getting better, bur rather worse. Note that data is not only raw data, but also schema, consistency, stability, predictability and lack (or separation) of clutter.
I’ve mentioned some of a number of cartography commissions (“directions” if you wish) which ICA is busy with, OSM is doing nothing on any front. Although there have been people and attempts in OSM community to do that.
Note: OSM-Carto is NOT a Cartgraphic style, It’s creators are doing a great, hard and eseential work maintaining data visualisation for mappers, but that project has never had a task to create a cartographically correct map and it never had resources to do that (and in my opinion it should ONLY be shown to mappers, not final users). Plus mind of contemporary person is spoiled by other very popular and also cartographically weak maps - Google/Apple/Bing maps (in this group OSM-Carto would be the best :-).
Comment from Mateusz Konieczny on 5 January 2022 at 08:06
I think that proposing something specific and something that actually can be done would be a better solution than insulting people.
Or at least do both, just insults and vague complaints about everything getting worse are not going to change anything.
On which level there is lack of QA measures/guidelines? Is it about tag creation/deprecation/use?
While viewpoint of “proposal process as it stands and ‘Any tags you like’ is harmful” can be internally consistent, claiming that there are is “absolute lack of QA measures/guidelines” is not consistent with reality.
Comment from Mateusz Konieczny on 5 January 2022 at 08:07
Can you give some examples?
Comment from Tomas Straupis on 5 January 2022 at 08:41
Yes, procedure of data schema modification does not have any QA. I’ve proposed possible solutions:
Main problem here is how to pick the professional commission. Waving certificates or professional experience does not sound feasible.
I’ve mentioned some ICA commissions in original post, but you can find a full list here: https://icaci.org/commissions/
P.S. “wiki proposal” process is a joke. 10-20 random people voting on some wiki is just absurd. It is not professional, it is not quality work, it is not representative. There is no point of even mentioning it.
Comment from Mateusz Konieczny on 5 January 2022 at 08:51
It is a bit misleading and confusing to describe guidelines you dislike or consider as useless/harmful as “absolute lack of QA measures/guidelines”.
Even if it would be based solely on haruspicy then it would be misleading and confusing to describe it as “absolute lack of”.
Comment from Mateusz Konieczny on 5 January 2022 at 09:00
From looking at it - “OSM is doing nothing on any front” seems clearly untrue, unless by “is doing nothing” you mean “is doing nothing that I like” - like with QA.
Comment from Tomas Straupis on 5 January 2022 at 09:21
“QA” done by people who have no experience in Carto/GIS/IT is a joke. Can one do a QA of surgeons work? I guess no, even if one has red something about it on the internet but has no experience with it. One cannot READ experience. Number of posts one makes on every possible topic is not experience. Why would that “one” then think that he can do QA for Carto/GIS/IT things?
Can you give examples of what is OSM doing on cartography front?
Comment from amapanda ᚛ᚐᚋᚐᚅᚇᚐ᚜ 🏳️🌈 on 5 January 2022 at 21:00
If you want a version of OSM that has gone through a QA process, then you can make that yourself today. Commission your group of professionals, and start! All the data is available. If you make something good, then people will use it. Facebook are threatening human rights but they are making an OSM data distribution like this.
I’m on the OpenStreetMap Foundation Board, so I pay attention when people complain when we’re doing something wrong. Yes, these sound like issues that are affecting you, but I don’t see how I can help here. It’s very easy to point out what’s wrong, and it would be nice to think that “can’t someone else do it?”. But I don’t have a magic wand. You don’t need my permission to make an OSM data distribution with some different QA rules. So why not do it?
Comment from Tomas Straupis on 6 January 2022 at 07:21
Amanda, you’re missing a point here. We CAN and ARE doing special QA for our country (Lithuania) - no problem with that. What I’m saying is that without a change in the way QA is done in OSM as such, it will remain in the outskirts of GIS as a cheap, temporary and unreliable DATA source without ANY innovation in Carto/GIS. And even data part is endangered with the rise of INSPIRE in Europe and Natural earth globally.
My impressions from ICC is a way to get out of OSM information bubble.
Some papers have been published/discussed in science list, Frederik’s student(?) has published interesting work on parallel road collapsing. But those were just momentary pops. And that’s it, nothing came from that (at least in OSM).
Comment from Mateusz Konieczny on 16 January 2022 at 14:47
“Commission on Maps and the Internet”
Maybe OSM is not doing anything that you like on this topics, or people doing it are without proper credentials that you want, or you disregard their Carto/GIS/IT experience.
But “OSM is doing nothing on any front” is clearly and blatantly false.
Comment from Tomas Straupis on 16 January 2022 at 19:07
Mateusz, it is the second message you write claiming that there is something done by OSM on Cartography, but fail to provide SPECIFIC examples. I could be wrong, there might be something hidden in the dark corner, so please shed some light on it. (Credentials are irrelevant, knowledge and effort is essential)
Comment from Mateusz Konieczny on 16 January 2022 at 19:59
https://github.com/ZeLonewolf/openstreetmap-americana for example
I am not trying to convince you that it is cartography that you like or appreciate - but it is cartography nonetheless.
Claims less aggressive than “OSM is doing nothing on any front” may be harder to disprove.
Comment from Tomas Straupis on 16 January 2022 at 21:35
If this is the only example you can present, then it proves my point very well.
OpenStreetMap-Americana is just another simple style… Simply changing colours is not cartography. You cannot show this map to cartographers as it is full of standard errors, just as most simple maps (even with it’s very restricted set of object classes being displayed - mainly high level roads - which makes the task much easier).
Comment from Mateusz Konieczny on 16 January 2022 at 22:12
I am not going to spend hours on making thorough overview, given that single exaple of anything at all is a sufficent counterexample to this clearly false claim.
Comment from Mateusz Konieczny on 16 January 2022 at 22:14
Cartography is in general defined as “study and practice of making and using maps” or similar.
Making any maps at all, even really bad ones and in outrageous projections as web mercator is still cartography.
In the same way as writing useless program in a terrible way is still programming.
Comment from Geonick on 16 January 2022 at 23:54
Tomas wrote Tomas asked: > Can you give examples of what is OSM doing on cartography front?
Yes: Looking at “Maps Exhibition” you’ll see the two map products which rely on OSM: My “Castle Dossier Map - Switzerland and neighbouring countries” presented by the Swiss Society of Cartography https://www.icc2021.net/ (direct link: http://www.geografia-applicata.it/en/icc-2021-virtual-exhibition/ ) as well as “swisstopo Vector Tiles” by Dominik Käuferle, Sebastian Denier, Petr Pridal, Nicolas Bozon. Plus there is “ContextMaps” by Institut Cartogràfic i Geològic de Catalunya.
Then there have been two presentations with OpenStreetMap in the title(!): “Cultural Heritage and Awareness: Differences Between Volunteered Geographic Information of Openstreetmap and an Official Cartography. The Case of Caserta in South-Italy” - and “Soviet City Plans and Openstreetmap: a Comparative Analysis”.
The ICA Workshop on Map Generalisation and Multiple Representation explicitly mentions OSM: https://generalisation.icaci.org/prevevents/workshop2021.html and the orienteering event too: https://www.icc2021.net/orienteering/
Comment from Geonick on 17 January 2022 at 00:20
Tomas,
I’ve several questions to you statements in your diary and an own hypothesis. Disclaimer: I’m a member of the Swiss Society of Cartography and a board member of the Swiss OpenStreetMap Association.
First, doing a quick search on Scholar https://scholar.google.ch/scholar?as_ylo=2021&q=cartography+openstreetmap receals 1200 papers related to Cartography and OSM. And there are 7 occcurrences of OSM in the ICC2021 programme. So I wonder how you could overlook this?
Secondly you stated: > (Well it is) because OpenStreetMap (community) is not only doing nothing in cartography front, but (…) to do some quality/cartography work is quickly pushed away
I’m sorry for that: Can you be more specific about your experiences?
Third: My impression is the other way round: Cartographers are doing almost nothing on the volunteered geographic information (or citizen science) front - besides “just” using OSM without mentioning it! My hypothesis is, that traditional cartographers are simply “afraid” of automated digital map production. And it’s people like you an me to explain to them, that their expertise still is needed there.
Comment from Tomas Straupis on 17 January 2022 at 06:41
Well I did mentioned that OSM is used (and mentioned) as a data source in quite a lot of presentations (in general as well as in ICC2021). But that is the problem - OSM is JUST a data source with expected data quality much higher than it really is and I’ve mentioned some reasons for that (as I see it).
But my whole point is that besides data there is nothing being created, invented in OSM which you could present in Cartography conference. There have been some occasional results: Frederiks student(?) has written a paper on collapsing dual carriageway (interestingly coming to opposite conclusion than I did several years before that:-), but again I’m not sure we can count that as “OSM”.
Regarding what cartographers are or are not doing with OSM. Besides the data there is currently no group(s) doing cartography research/inventions in OSM which cartographers could get involved into. I participate in discussions of a commission of generalisation and multiple representation. That group alone is entirely concentrated on automated digital map production. Budgets of national mapping agencies are going down everywhere (well except Switzerland?:-) so all of them are very much interested in automating as much of digital map production as possible. And there are advances in technical implementation (of generalisation operators) as well as theoretical part (my favourite is vario scale maps). There is a discussion of how much quality you want to retain while going to auto mode as algorithms are still lagging behind what human cartographers could do (maybe that is why say SwissTopo main map is being updated manually after automated notification of where and what changes have happened on the ground). But in general cartographers are very much keen on automating more and more of their map production. Currently that stands by different estimates at 60-90%. It is not 100% not because cartographers are “afraid” of automation, but because they have to comply with very specific quality requirements.
Comment from Geonick on 17 January 2022 at 13:51
Once again: My “castle dossier map” is an example presented at ICA2022 as well as the “swisstopo lightbase map”.
Oh: You are in the commission of generalisation and multiple representation? I know some researchers there. This reminds me how still visually (even paper) oriented many established (NMA) cartographers are thinking when speaking about “multiple representation”. Any properly desigend spatial database is “scaleless” and capable to serve to automated processes which represent mutliple representations.
My main point is, that cartographers - especially from NMAs - are indeed interested in (semi-)automation - but only under their full control and only concentrating on their own data.
There are shy initiatives coming up, like the MOU the US Chapter made with US-Gov’t. and smaller NMA cooperations. Then there is e.g. some research in maps for the blind with heavy use of OSM data, like in theses not-so-recent-anymore papers: “Automatic Derivation Of On Demand Tactile Maps For Visually Impaired People: First Experiments And Research Agenda” (2019). https://hal.uca.fr/hal-01980146/document and “Automatic (Tactile) Map Generation—A Systematic Literature Review” (2019). https://www.researchgate.net/publication/334072539_Automatic_Tactile_Map_Generation-A_Systematic_Literature_Review
P.S. I’m going to publish a study soon here about “OSM for administrations” https://wiki.openstreetmap.org/wiki/DE:Public-OSM_Partnership .
Comment from Tomas Straupis on 17 January 2022 at 14:35
I had some contacts with swisstopo regarding their lightbase map. Had an idea of joining their expertise in making the famous SwissTopo map with today’s technologies used in lightbase map, but that direction kind of stalled. And integration of that experience is essential, without it it is just another openmaptiles map. There is much more in cartography than choosing colours. For me any map where smaller scales have not been at least partially generalised are not cartographically sound maps.
I remember the first time I was told that official map data come in different scales, I thought that it is a waste of time and resources - you can calculate everything from the largest scale! But years of reading papers, analysing maps, making maps and talking to other cartographers proved the necessity of data in multiple scales. Well at least to me personally :-) And ironically new technologies like vector tiles are increasing the need of proper generalisation. And this is a different topic anyway…
Comment from Geonick on 17 January 2022 at 20:42
Many cartographers consider OSM as competition to NMA data, some deliberately denigrate OSM. But OSM is a complement.
Why should the OSM community get involved in such a congress? Hardly any cartographer or researcher using OSM has done an edit in OSM yet - as recommended by Prof. Muki Haklay. And I hardly know any cartographer who is involved in an open source project - at least not in Europe.
Do you have an explanation what prevents cartographers to contribute to the OSM carto style https://github.com/gravitystorm/openstreetmap-carto/blob/master/CONTRIBUTING.md or to publish a professional map style based on known vector tiles?
Comment from Tomas Straupis on 17 January 2022 at 21:43
OSM and NMA data have different purposes, strengths and weaknesses. Combining them can create a great thing. But that is a different (interesting) topic.
Editing OSM is getting harder as you notice that it is a moving target. It is part of the problem which I’ve raised: there is a small number of people who do not understand cartography and are systematically (I’m sure unknowingly) destroying data value (because of a total lack of any QA) which is very demotivating and if you have access to stable data it is hard to convince to contribute to OSM anything more than thematic/specific data. (I personally am contemplating stopping contributing to OSM basemap features in favour of stable and nicely classified NMA data).
Regarding open source projects: have you heard about CartAGen? Open source generalisation package. Made by Guillaume Touya (IGN France), chair of generalisation commission.
Regarding contribution to OSM-Carto. The reason is very simple: OSM-Carto never had a purpose to be a cartographic map (very misguiding name chosen) - and for very well understandable reasons. Kudos to it’s creators - OSM-Carto is a very well made data visualisation for mappers. In order to convert it to cartographic map and thus attract cartographers to contribute - you would have to:
And regarding the last one - “or to publish a professional map style based on known vector tiles” - I think the magic part of cartography happens while creating those vector tiles, not while colouring them ;-)
Comment from impiaaa on 18 January 2022 at 05:47
Correct, OSM is first and foremost a database for building world maps, not one singular map. Therefore cartography is entirely irrelevant to the project. OSM strives to document the world as it exists, not produce some cartographer’s subjective interpretation. Stop trying to use OSM to platform your political agenda.
Comment from Mateusz Konieczny on 18 January 2022 at 09:06
I want to note that it is seems to be a tautology or at least unusual term.
Note that https://www.google.com/search?q=%22cartographic+map%22 finds mostly blog spam and discussion concerning computer game mod.
Making any map, including low quality ones is also part of cartography.
While substation sub_station attracted negative comments ( https://github.com/gravitystorm/openstreetmap-carto/issues/230#issuecomment-29238913 ) and there are some issues about similar changes…
This is not actually a serious problem and actual effort wasted on that was pretty minimal.
Given that one of primary uses of OSM data is making maps and nearly every OSM editor presents data for editing as a map… Design of map style in editor is also a cartography.
You keep repeating clearly false claims, while it was initially entertaining to respond I guess I should stop wasting time.
Comment from Tomas Straupis on 18 January 2022 at 09:48
Mateusz, if you create a crappy program it is still programming, but you do not call yourself a “programmer” then. The same with cartography. There might be a problem with information bubble regarding cartography in OSM community. That is why it is good to get out of the bubble: read books or visit conferences (talk to people out of the bubble).
QA is a pretty complex thing and in order to understand it you need at least some experience in IT/GIS which you obviously do not have :-)
And the topic of this post was about lack of cartographic research/science/innovation. You do not go to the conference just to show yet another X, you go to the conference to show something NEW. There is nothing wrong being simply an cheap earth digger, but personally I would like something more.
Comment from Geonick on 18 January 2022 at 23:24
Tomas
I hope you aren’t a troll. You repeat that there would be a “total lack of any QA”. As a long time mapper you surely know an activity and a tool from here https://wiki.openstreetmap.org/wiki/Quality_assurance . So pls. explain yourself what you are referring to.
You wrote: > there is a small number of people who do not understand cartography and are systematically … > destroying data value (because of a total lack of any QA)
I still can’t follow you - pls. give specific examples to… 1. What has QA (of source data and/or tagging schema) to do with cartography? 2. Where was “data value” being destroyed in OSM?
Many NMA mappers think at the beginning that they can just dump their (allegedly) stable data into OSM. As a long time mapper you know that this is not possible - the QA of OSM says that data should not be inserted twice and the topology must be correct.
The OSM dataset has proven that it is stable enough to serve typical geospatial use cases including professional cartographic products.
Yes. This exception confirms the rule (i.e. my statement above).
You seem to underestimate the visualization possibilities of Vector Tiles.
But yes: Vector Tiles contain highly generalized graph-less data in the upper zoom levels: see e.g. the production process of OpenMapTiles. But nobody prevents you from performing model generalization and cartographic generalization on this data.
Yes. But you can find the people you need at the NMAs, universities and professional map publishers.
Did any presentation of the ICC 2021 or a previous ICC have Vector Tiles as a topic (except “swisstopo Vector Tiles”)? I can find presentations about this at State-of-the-Map and FOSS4G.
Comment from Tomas Straupis on 19 January 2022 at 09:56
When I talk about lack of QA, I’m not talking about technical tools: those do exist and are pretty easy to implement locally. I’m talking about QA on a higher level: there is currently no QA on the changes of tagging schema - schema is changed by a tiny group of people most of whom have absolutely no understanding of the subject matter, no long term goals or strategies. Cost/benefit of change of schema is not analysed which allows changes with high cost and low benefit to go through. This makes tagging schema not only unstable, but inconsistent and at times moving to being less useful from cartographic perspective.
Cartography is pretty sensitive to proper/logic tagging schema - everything is interconnected: say for building typification on small scales we have to turn the building symbol towards the closest way - what is the distance to look for the way? can that be a QA rule for how far a building must be from the road? what type of the building? what type of the road? what is the hierarchy of the road classification? This is just to give an idea of how things are interconnected. You CAN make all those rules work and this makes the schema consistent as a whole, not some heterogenic small pieces through here and there.
Waterbody tagging: large bodies like lakes/reservoirs are symbolysed in a totally different way than rivers and also in a different ways than small waterbodies (basins, ponds and the like). Why are they being lumped up into one pile when they have been correctly separated for years from the very beginning of OSM?
These are just examples, no need to discuss in details here.
Regarding NMA, maybe you have some bad experience. In my experience they understand very clearly that OSM data is already too saturated to simply “dump” ANY data into it. The advantage is using OSM and NMA (or any other) datasets as a complex in a process of updating and QA’ing of BOTH datasets but separately.
“You seem to underestimate the visualization possibilities of Vector Tiles.” - can you give a short description of idea: how do you typify buildings coming in a vector tile? how are you going to FIT that amount of building data in vector tiles in the first place (without typification) say on zoom level 12 in large cities? In my experiments 3-5 years ago pretty decent phones (nexus at that time) were crashing on tiles with 3-5Mb of data.
“Did any presentation of the ICC 2021 or a previous ICC have Vector Tiles as a topic (except “swisstopo Vector Tiles”)?” - yes of course. Vector tiles is not a new technology. New kid on that block is varioscale maps (I’ve only seed one practical implementation of that). Comparing to raster, vector tiles add possibility to adjust symbolisation and switch on/off some layers, they also increase the importance of generalisation (simple DP and snapping to grid which is done because of technicality of VT is far from being enough). Generalisation work stays the same regardless of VT.
Even such slow moving behemoths as ESRI have already implemented vector tiles in their technology and even stopped presenting them on conferences because well… it is not “new” any more.
BTW: it looks we have a very different understanding what “cartographic generalisation” is. I’ve made a new post today with a link to a pretty good (and kind of short) description of generalisation - https://newsly.org/en/Cartographic_generalization-8042826286.
Comment from Geonick on 19 January 2022 at 15:13
You wrote
This is a crowd sourced project and “changes of tagging schema” are heavily discussed.
No; Tags are changed sometimes changed by too many people.
Don’t be arrogant - put your arguments forward.
Processing OSM data for a cartographic product is like any other big data project: see the V’s von Big Data especially variety. If something is not new here, then it’s the scientific research which attributed OSM as definitely being “fit enough” to be even compared to “professional” data.
You speak of minimal distances to maintain readabiliy at a certain scale? That is entirely part of cartographic postprocessing.
Regarding classification and waterbody tagging: This is indeed again doable in OSM data processing. Many interesting questions to solve and publish here.
Pls. look at the papers about maps for the blind where - like with processing for Vector Tiles - it’s about generalization in extremis and to loosely cite two statements from there: There is no automated process available yet (except Mapy and in closed ArcGIS Pro). And there are no attempts to integrate data from different NMA’s. And regarding proper classification: Even cartography found an agreement of POI classes.
By tags and postprocessed attributes like “class” and “type” (or so) in OpenMapTiles.
Postprocessing OSM data to Vector Tiles or to any other map oriented db is still an area with much innovation potential to apply and extend cartographic map generalization (wich I know better than you suggest).
I still can’t find much papers (actually none at ICC) about vector tiles and open source repositories - especially not vario-scale maps.
My main point is really not to bash NMAs but to say: Don’t expect more from OSM community than what the cartography did not achieve.
As a mapper it’s up to you to do interesting cartographic stuff with OSM. And reach out the NMA and cartographic researchers to tell them, what they could do more with using and integrating OSM with NMA data (especially regarding base maps, POIs, geocoding, and routing).
Comment from Tomas Straupis on 19 January 2022 at 16:35
This is one specific map quality criteria. In that particular paragraph I was talking about whole schema consistency, schema working as a whole not as millions of separate incompatible fractions. Also about goal, strategy, change rules. All of that is missing.
I see no building generalisation on OpenMapTiles (on zoom 12 some (detached?) buildings are removed). No building typification and even no building simplification. Maybe I’m looking at some wrong place (https://www.maptiler.com/maps/#topo//vector/13.17/25.35044/54.71288)? And actually… no generalisation of any data (besides DP and SnapToGrid), what am I missing?
Summarising: you’re saying OSM is not for cartography. OSM data is chaotic, unstable but that is fine - c’est la vie. One must do some kind of ETL/transforming to good schema (thus isolate from the chaos of OSM schema) and then do all cartography outside of OSM, maybe with NMA, maybe with non-OSM cartographers/scientists. Well, this is what we currently have anyway and that is the reason for this post in the first place.
For thoughts: to my knowledge most (all?) uses of OSM in professional way are transforming OSM data to some proper schema and then doing serious clean-up/postprocessing (and that is BEFORE doing any generalisation). What does that say about OSM data schema?
Comment from Eiim on 19 January 2022 at 16:50
I took a look around me, and there does appear to be some very subtle building simplification, most noticably on rounded buildings. It also appeared that some very close buildings were merged around zoom 14, although that may just be a rendering quirk.
I’m looking at https://www.maptiler.com/maps/#topo//vector/13.83/-84.73729/39.51232
Comment from Tomas Straupis on 19 January 2022 at 17:08
Yes, Eiim, you’re right, there is some amalgamation done.
original:
generalised:
Smaller buildings removed and those close enough grouped (amalgamated) into larger ones. And some apparently non building-specific simplification was used (as square edges have not been preserved?).
Good. But still no typification - the reason I point to typification specifically is that typification although looks simple, is much heavier than simplification because it needs to look at neighbouring objects on different layers (buildings and roads) - which is harder to do with vector tiles as you might need data from neighbouring tiles, you need distance search which needs indexes etc.
P.S. This should NOT be taken as a critique of OpenMapTiles - it is a marvellous product. Generalisation I write about is complex and requires a lot of resources which without some additional research would rise costs more than users would want to pay for such an improvement.
Comment from Geonick on 19 January 2022 at 19:30
Correction: I wrote “Even cartography found an agreement of POI classes.” whereas I meant it obviously did not find a classification for POIs - even not a simplest common one: See my wiki here https://giswiki.hsr.ch/POI#POI-Kategorien . And it’s no need: It’s up to you to define the purpose of the derived map.
No. I’m saying it’s inevitably homogeneous to a certain degree but still fit-for-use for cartography among many more usages.
Exactly! That’s the workflow: data > postprocess > render. There is one (OSM) dataset of the world serving many purposes (base maps, routing, etc.). “Don’t map for the renderer”, i.e. don’t impose varying needs from downstream processes to the spatial data source.
It tells us, that the OSM data schema is as diverse as reality is and it’s changing as reality is changing (see e.g. childcare). There is a continuum between a “stable” and centrally defined schema and a heterogeneous, decentrally defined schema, where NMA and OSM stay an both ends. The latter is much more up-to-date (meaning minutes versus years) containing 1001 POIs (versus some dozens) and which allows routing.
The real current challenges for both, NMA cartographers and OSM enthusiasts is to look for integration and synchronization (post-)processes.
Another interesting challenge would be to typify, as you suggested. Here, one could look into editor presets and semantic nets. I’d be happy to look at your open source repo about your work.
Comment from Geonick on 19 January 2022 at 19:56
To make it clear again: Expert people like cartographers and geodesists often initially imply that OSM is of lower quality than “official” data.
However, research on geodata quality (completeness, logical consistency, positional accuracy, temporal quality, thematic accuracy and usability) has become uninteresting since everything points to OSM being fit-for-use.
Lewandowski & Specht (https://doi.org/10.1111/cobi.12481) go even further and state “Collectively, these data suggest that volunteer data are not consistently more variable than expert data”.
What is in fact could be enhanced in OSM are tools and map (visualizations) that indicate e.g. completeness. Here’s a shy attempt from some of my students https://eprints.ost.ch/id/eprint/940/ .
Comment from Tomas Straupis on 19 January 2022 at 20:09
It tells us that OSM data schema is random/unstable/illogical and is getting worse. It is as diverse as people changing that schema without any common goal or strategy.
You ALWAYS have to convert it into something usable. Probably a good business case for the likes of geofabrik for raw data ;-)
Typification is one of generalisation operators where you take a number of features (usually of one type) and replace them with one or few to represent the TYPICAL situation in that area as it is impossible because of lack of space to represent all real geometries.
For example to represent an area of small houses (say 50) on a smaller scale you simply display say 10 squares distributed in the same area (displaced from roads, oriented towards the road). Or instead of displaying 100 trees you display 20. Etc.
It is one of generalisation operations which it would be completely impractical to do as a post-processing of data from vector tile on client side. The same with most other generalisation operators, especially the ones requiring knowledge of the surroundings: displacement, road-network-pruning, amalgamation/aggregation etc.
Comment from Tomas Straupis on 20 January 2022 at 06:27
Thank you - very interesting and well written article. It would be nice to try it on Lithuania. I wonder if the results would be different if ortophoto would be removed altogether. As other data like landuse, buildings in my opinion should correlate with shop count much stronger than ortophoto data (together with building height mentioned in the article and not mentioned some classes of ways).
However this is all about data which we seem not to have any disagreement. My post was about cartographic research and innovation and what influences that - data schema management.
Comment from Geonick on 21 January 2022 at 13:43
Please stop these insinuations and false statements. As I said, there is hardly any scientific research left on the topic of data quality, because the OSM data is proven to be fit-for-use. See the 100+ papers on this: https://scholar.google.com/scholar?q=openstreetmap+quality
The possibility that people can change the schema is an advantage and even a necessity among other things to be able to cope with local situations. And the common goal is a digital representation of the world.
Exactly. And that’s because OSM has a key-value schema, which you typically want to convert it into a tabular (GIS) form. This already includes classification and aggregation: See not only the Geofabrik document (https://download.geofabrik.de/osm-data-in-gis-formats-free.pdf ) but also https://openmaptiles.org/docs/ or my OSMaxx schema documentation https://github.com/geometalab/osmaxx/blob/master/docs/osmaxx_data_schema.md .
Agreed that post-processing based on Vector Tiles (VT, specifically Mapbox VT format) can be impractical - though that could be still an option if you want to scale up. See for example the OSM QA Tiles https://osmlab.github.io/osm-qa-tiles/ .
The typification you describe fits very well with the pipeline, procedures and tools needed to generate VT. See e.g. https://github.com/openmaptiles/openmaptiles-tools or https://github.com/geofabrik/openstreetmap-carto-vector-tiles/blob/master/README_VECTOR_TILES.md .
This seems to be a good place to engage yourself. And that what I meant when I said that I’d wish NMA and cartographers could do more.
To sum up and to clarify especially for you:
Comment from Tomas Straupis on 21 January 2022 at 14:10
Again, I’m talking about data SCHEMA and the strategy and rules for SCHEMA, not data. Declaration of schema being random because “world is random” is simply trying to declare a bug as a feature - excuse to do nothing. Creating SCHEMA rules would not mean prohibition of adding new tags or changing existing ones, it should control how/when/which existing tags are changed, where new tags are placed in the topological hierarchy (say landuse=education or landuse=residential+residential=education or landcover=education or whatever)
This is a technical and irrelevant detail. These two types of representation can coexist and have no influence. You would have to convert osm key-value schema to a usable tabular OR key-value schema to be used professionally.
Neither tabular nor key-value is a “GIS form”. Both can be used for GIS (f.e. PostGIS).
It is impossible to build something on top of random, unstable schema which lacks any direction, which can and is changing to worse. If we have ETL between OSM data and cartography, then it is no longer OSM and OSM can then easily be replaced with other data with more stable and logical data schema. And if we remove emotions and attachments there would be no practical sense to use OSM for base data (landuse, forests, building, places etc.).
Well, that is what I am saying from the very beginning - OSM is currently limited to JUST DATA with no QA for schema.
Comment from SomeoneElse on 21 January 2022 at 15:32
Geonick wrote:
Alas, I think that time has shown that Tomas is little more than a troll, and seems to tke great delight in “conversations” such as these with contrbutions that really don’t add any value. As the saying goes, never wrestle with a pig - you both get dirty and the pig likes it.
Comment from Geonick on 21 January 2022 at 19:55
Yes. It would be nicest if he followed up now with actions after all the words.
Specifically, he and cartographers and db engineers could try to understand the pipeline for generating VT and then improve it (see e.g. here as starting points https://github.com/systemed/tilemaker/blob/master/docs/CONFIGURATION.md or here https://github.com/openmaptiles/openmaptiles/blob/master/layers/landuse/landuse.sql z13 - z6).
And if that is too much to expect - because of programming knowhow (Lua, SQL) - then I would be happy with a contribution on a scientific map generalization workshop or an ICC paper :-).
Comment from Tomas Straupis on 21 January 2022 at 22:35
Well, my whole point is that there ARE people (not only me) who would LOVE to add cartography and other knowledge/solutions to OSM (and have already tried to do that), but we CANNOT do that because of the barriers described above.
Could you be more specific as what should I and others have to understand about vector tiles? Given our sandbox https://topo.openmap.lt with all code for this openly on github and a pile of ideas on future improvements. What steps/knowledge of the process do you think are we missing?
Sorry, I did not get that. Are you suggesting to write a paper to ICC, or should I (and others) add credit to OSM in our ICC papers/presentations? What’s the deal? :-)
P.S. Writing code is always the least of the problem. Lack of ideas/knowledge/algorithms is a problem.
Comment from mboeringa on 17 September 2022 at 17:36
Tomas and Geonick, you may find my SOTM 2022 poster interesting (although still project in development) ;-): https://files.osmfoundation.org/s/xDdDz3rpQX2C7FJ