Re: [Talk-GB] OS OpenData StreetView Tiles now available
Steve Doerr steve.do...@... writes: In fact, filling in the street-names of an area that's already been mapped strikes me as an ideal project for a newcomer- especially if they haven't actually got a GPS. Personally, I would have thought that a bigger issue (than street-names) is gathering POIs. I can see that, where the street layout is already mapped, people are much less likely to be up for slogging around gathering way-points for schools, churches, pubs, etc. We could always deliberately delete some of the street layout and names in order to motivate people to get out and map. Personally, I would feel it greatly demotivating to feel I was spending my mapping time surveying something that could equally well have been added by using the taxpayer-funded and mostly high-quality OS data. However, adding buildings from OS will provide an excellent newbie task: finding name, address, and amenity for each building. -- Ed Avis e...@waniasset.com ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] OS OpenData StreetView Tiles now available
On 07/04/10 09:45, Chris Browet wrote: For clients supporting multiple projections, wouldn't it be best to have a WMS (preferably a WMS-C) allowing to choose between the 2 projections (+ EPSG:4326, maybe)? It might be that http://os.openstreetmap.org/wms/map.php?source=sv; http://os.openstreetmap.org/wms/map.php?source=sv; allows it, but I can't get the capabilities... That would require us to have two sets of tiles which makes it unlikely as keeping two copies of everything would be a bit silly. The WMS is very simple one that somebody wrote in PHP so probably does the minimum necessary to make JOSM work. Tom -- Tom Hughes (t...@compton.nu) http://compton.nu/ ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] OS OpenData StreetView Tiles now available
Hi, Tom Hughes wrote: For clients supporting multiple projections, wouldn't it be best to have a WMS (preferably a WMS-C) allowing to choose between the 2 projections (+ EPSG:4326, maybe)? It might be that http://os.openstreetmap.org/wms/map.php?source=sv; http://os.openstreetmap.org/wms/map.php?source=sv; allows it, but I can't get the capabilities... That would require us to have two sets of tiles which makes it unlikely as keeping two copies of everything would be a bit silly. You could use the recently open-sourced http://mapproxy.org/ instead of the very simple WMS that someone wrote in PHP. Mapproxy combines tiles and scales or even reprojects them to fit any WMS request. And offers proper GetCapability responses. The image quality is of course less than stellar if you request images in any other projection/resolution than supported by the original tiles. Bye Frederik ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] OS OpenData StreetView Tiles now available
On 07/04/10 09:58, Frederik Ramm wrote: You could use the recently open-sourced http://mapproxy.org/ instead of the very simple WMS that someone wrote in PHP. Mapproxy combines tiles and scales or even reprojects them to fit any WMS request. And offers proper GetCapability responses. The image quality is of course less than stellar if you request images in any other projection/resolution than supported by the original tiles. Well I could, except that it seems to be a complete server that needs it's own port, which is a problem for us. I guess I could reverse proxy to it from apache. It looks horribly complicated to setup though. Tom -- Tom Hughes (t...@compton.nu) http://compton.nu/ ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] OS OpenData StreetView Tiles now available
On Wed, Apr 7, 2010 at 10:51, Tom Hughes t...@compton.nu wrote: On 07/04/10 09:45, Chris Browet wrote: For clients supporting multiple projections, wouldn't it be best to have a WMS (preferably a WMS-C) allowing to choose between the 2 projections (+ EPSG:4326, maybe)? It might be that http://os.openstreetmap.org/wms/map.php?source=sv; http://os.openstreetmap.org/wms/map.php?source=sv; allows it, but I can't get the capabilities... That would require us to have two sets of tiles which makes it unlikely as keeping two copies of everything would be a bit silly. Well, if it has been deemed reasonable to make the tile available through WMS/TMS, I don't see the silliness of having them unaltered in the first place, then maybe reprojected... ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] OS OpenData StreetView Tiles now available
On 07/04/10 10:18, Chris Browet wrote: Well, if it has been deemed reasonable to make the tile available through WMS/TMS, I don't see the silliness of having them unaltered in the first place, then maybe reprojected... That presupposes that we have a set of OSGB tiles. We don't, we have a set of large tiffs in OSGB projection which would have to be chopped up into tiles. Tom -- Tom Hughes (t...@compton.nu) http://compton.nu/ ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] OS OpenData StreetView Tiles now available
On Wed, Apr 7, 2010 at 11:20, Tom Hughes t...@compton.nu wrote: On 07/04/10 10:18, Chris Browet wrote: Well, if it has been deemed reasonable to make the tile available through WMS/TMS, I don't see the silliness of having them unaltered in the first place, then maybe reprojected... That presupposes that we have a set of OSGB tiles. We don't, we have a set of large tiffs in OSGB projection which would have to be chopped up into tiles. If they have been chopped AND reprojected for the TMS, I don't see the issue of having them only chopped... although, for a WMS, I'd guess they should probably be glued together, instead, if necessary... ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] OS OpenData StreetView Tiles now available
I began producing a second set of tiles in addition to RichardF's scripted set that uses a slightly different production method. Both rely on gdalwarp at the core, and this can be assumed to be correct (I hope!) Both sets were generated using z16 as the base resolution, and both can be compared here: http://edgemaster.dev.openstreetmap.org/streetview_tiles/ossv.html?zoom=16lat=60.51376lon=-1.05105layers=BTT I can see at most a 1px shift between the two. Chris Browet wrote: I'm not too sure the reprojection from EPSG:27700 (OSGB36) to EPSG:900913 (Google) went perfect. In Merkaartor, it is possible to load the OS Street View tiles directly and to use the EPSG:27700 projection (see below). Check http://picasaweb.google.com/lh/photo/x93nMda7mBrfra8AKbrj5g?feat=directlink for example. Now compare with the same area in potlach using the TMS: http://picasaweb.google.com/lh/photo/bHXkZ1jOB7v_JpiUmMlE5w?feat=directlink It seems the TMS is constantly shifted a couple of meters SE (this assuming the OSM'ers are right, of course). For clients supporting multiple projections, wouldn't it be best to have a WMS (preferably a WMS-C) allowing to choose between the 2 projections (+ EPSG:4326, maybe)? It might be that http://os.openstreetmap.org/wms/map.php?source=sv; http://os.openstreetmap.org/wms/map.php?source=sv; allows it, but I can't get the capabilities... Regards - Chris - How to load OS Street view tiles in Merkaartor: --- - Be sure the .TIF files and the corresponding .TAB are in the same directory - Layers - Map - ... - GeoTIFF - Load image... and select the tile(s) to load - Layers - Map - GeoTIFF - Zoom to center on the tile How to use the EPSG:27700 (OSGB36) projection in Merkaartor: - - if using svn trunk, just View - Set projection - OSGB36 (EPSG:27700) - if using 0.15, first add the projection by going to ~/.merkaartor/Projections.xml and adding the following projection line: Projection name=OSGB36 (EPSG:27700)+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.999601 +x_0=40 +y_0=-10 +ellps=airy +datum=OSGB36 +no_defs/Projection On Wed, Apr 7, 2010 at 00:07, Andy Robinson (blackadder-lists) ajrli...@googlemail.com mailto:ajrli...@googlemail.com wrote: The process of creating map tiles from Ordnance Survey StreetView in our required format is now largely complete (zoom 17 tiles not yet available) and can be viewed here: http://os.openstreetmap.org/ These tiles can now be used as a backdrop in editors. However before you start editing, please consider the following: 1. Don't assume the OS data is either correct or up to date. Use it as a guide and additional resource for your mapping, not a replacement. 2. Please add source tags to any data you add to OSM from OS StreetView. See the tag suggestions: http://wiki.openstreetmap.org/wiki/Ordnance_Survey_Opendata#Attributing_OS 3. If you're tempted to map in an area you're not familiar with, contact any local contributors first. Please don't alienate other contributors by treading on their toes. They will know their local area better than anyone else. 4. Look for places that have been mapped using Yahoo! imagery and don't have road names. This is a good place to start. 5. Avoid simply duplicating OS data in blank areas of OSM unless you're familiar with the area and don't have access to other resources such as a GPS. 6. In May the OS will release a further vector based product which may provide better data for buildings than tracing from OS StreetView. You might want to hold off tracing buildings until the details are confirmed. How to make use of these tiles: Potlatch: When the next version of Potlatch is live, you can just select 'UK: OS StreetView' from the background menu in the options box. Until then, just add this custom URL: http://os.openstreetmap.org/sv/!/!/!.png http://os.openstreetmap.org/sv/%21/%21/%21.png JOSM: Create a new WMS layer with the following url: http://os.openstreetmap.org/wms/map.php?source=sv; http://os.openstreetmap.org/wms/map.php?source=sv; or alternatively use the SlippyMap plugin for which you can find instructions of how to add custom tile sources at http://wiki.openstreetmap.org/wiki/JOSM/Plugins/SlippyMap#Custom_tile_URLS with http://os.openstreetmap.org/sv/ as slippymap.custom_tile_source_1.url Merkaartor: 1) In the Tools menu, open the TMS Servers Editor. 2) Add the following: Name: OS Street View Server address: os.openstreetmap.org http://os.openstreetmap.org Path: /sv/%1/%2/%3.png Tile
Re: [Talk-GB] OS OpenData StreetView Tiles now available
...snip... As a point of note while I was just doing a little test editing with these tiles, using the WMS function in JOSM I wasn't getting the necessary quality to read the street names, even with a change resolution request, so I swapped out to the slippy map viewer which was much better though I'm not convinced either method gets tile placement exactly right. ...snip... Ah, glad I'm not the only one re. the resolution difference in WMS and SlippyMap. Any idea why? ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] OS OpenData StreetView Tiles now available
Chris Browet wrote: I'm not too sure the reprojection from EPSG:27700 (OSGB36) to EPSG:900913 (Google) went perfect. If you're tracing from _any_ source without first aligning it with a trustworthy ground reference (typically an average of existing GPS tracks), You're Doing It Wrong. FWIW, the 'resolution limit' in most of all our mapping is people's unwillingness to draw anything more than rudimentary join-the-dots. cheers Richard ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] OS OpenData StreetView Tiles now available
Richard Fairhurst wrote: If you're tracing from _any_ source without first aligning it with a trustworthy ground reference (typically an average of existing GPS tracks), You're Doing It Wrong. It seems that the sort of offset that there is with the new OS data is different from what there was with NPE. Here, for example: http://edgemaster.dev.openstreetmap.org/streetview_tiles/ossv.html?zoom=15lat=53.19764lon=-1.74632layers=BTF There's a B road that is slightly S (5m maybe?) of where it should be in the OS layer, but correctish for the surrounding unclassified roads (based on underlying GPS traces). With NPE one whole area will tend to be a few metres to one side, whereas a km to the east or west it'll be offset differently - so (with Streetview) even after aligning the general area there might be still bits that need alignments correcting once traced. Obviously this requires multiple different good GPS traces - the area above should have those as it's relatively open and not a natural canyon as some of the surrounding areas are. There's quite a lot of NPE-traced data that isn't aligned properly. In the absence of any GPS traces if someone aligns it to OS Streetview it'll be an improvement, but obviously not as much of an improvement as actually going there and saying what you see. FWIW, the 'resolution limit' in most of all our mapping is people's unwillingness to draw anything more than rudimentary join-the-dots. Agreed, but even a straight line between two places where there's a road is better than nothing at all, and can be improved later. Cheers, Andy ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] OS OpenData StreetView Tiles now available
On Wed, Apr 7, 2010 at 12:42, Richard Fairhurst rich...@systemed.netwrote: Chris Browet wrote: I'm not too sure the reprojection from EPSG:27700 (OSGB36) to EPSG:900913 (Google) went perfect. If you're tracing from _any_ source without first aligning it with a trustworthy ground reference (typically an average of existing GPS tracks), You're Doing It Wrong. Ok, but let's be practical. Same goes for every GPS traces used to create OSM. There should be many for the same road, then averaged, etc... I'm not sure there is a large percentage of OSM data meeting these criterias... Re tracing, you cannot deduce the projection (especially a tricky one like OSGB36) by aligning a number of points. If the base projection is wrong and a simple translation do not solve the problem, then you're roasted... Did you do the aligning exercise to check the validity of the OS Street View tiles (in EPSG:27700) and the reprojected ones (in EPSG:900913)? - Chris - ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] OS OpenData StreetView Tiles now available
On 7 April 2010 12:53, TimSC mapp...@sheerman-chase.org.uk wrote: In both the edgemaster's and Richard's tiles there are periodic kinks (about 1 pixel in size) in what should be straight lines. It is more obvious in Richard's tiles because they are less noisy. Any idea what is causing that? The warping between OSGB36 (EPSG: 27700) and EPSG: '900913'. Richard's tiles use a custom conversion script with antialiasing on the resample. Edgemaster's tile used gdal2tiles. I'm working on some cleaned up and pngcrush'ed tiles, but do not expect them in the next few days. The existing tiles are more than good enough. / Grant ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] OS OpenData StreetView Tiles now available
Just to throw more things into the mix, I have a third set of OS Street View tiles, only z11-z15 though as my overall method's much slower :-( which was produced using a different workflow to the first two. I'm using TimSC's warp-gbos program that was used to rectify the Scottish Popular Edition maps. This reprojects each source TIFF (and coverts it to JPG), it then tiles the JPGs, choosing individual pixels where going across source image boundaries. I also see the characteristic kinks, but in different places. Mine seem to be generally *worse* (i.e. do not use mine for tracing!) although this might also be something to do with JPG compression. For some z16s I do have, compare: http://splintmap.geog.ucl.ac.uk/~ollie/osopendata/streetview/16/32760/21780. jpg and: http://a.os.openstreetmap.org/sv/16/32760/21780.png It looks like the os.osm set is correcting itself every few metres - hence those kinks appearing whereas I just have one big, horrible correction, about 70% down the tile. By the way you can see my set at: http://splintmap.geog.ucl.ac.uk/~ollie/osopendata/sv/ One thing I've already noticed, over and above the minor differences between the 900913 Street View sets, is how dramatically off the NPE maps are in certain places - GPS traces and OS Street View generally in agreement, while NPE can be off by ~2-300m. I redid a village last night which had been clearly traced in NPE - it was not good at all. None of the roads were connected to the other roads, and the GPS traces that were present for a couple of the streets were way off. I think the OS Street View-based tracing is now much closer to the truth. Ollie Date: Wed, 7 Apr 2010 13:34:26 +0100 From: Grant Slater openstreet...@firefishy.com Subject: Re: [Talk-GB] OS OpenData StreetView Tiles now available To: TimSC mapp...@sheerman-chase.org.uk Cc: talk-gb@openstreetmap.org Message-ID: t2hfd93759a1004070534k83cf578ck1b5cc71be78b5...@mail.gmail.com Content-Type: text/plain; charset=ISO-8859-1 On 7 April 2010 12:53, TimSC mapp...@sheerman-chase.org.uk wrote: In both the edgemaster's and Richard's tiles there are periodic kinks (about 1 pixel in size) in what should be straight lines. It is more obvious in Richard's tiles because they are less noisy. Any idea what is causing that? The warping between OSGB36 (EPSG: 27700) and EPSG: '900913'. Richard's tiles use a custom conversion script with antialiasing on the resample. Edgemaster's tile used gdal2tiles. I'm working on some cleaned up and pngcrush'ed tiles, but do not expect them in the next few days. The existing tiles are more than good enough. / Grant ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
