Hi, Very interesting. Maybe I don't get it, and this is already being done, but is there a way to store the X/Y to long/lat mappings in the EXIF header of a JPEG somehow after you've warped the image, then you could use the image as a raster map in moving-map applications? I think a couple of more affordable GPS navigation applications do this kind of thing already and it would help with map availability.
Thanks, Sam On Sun, 08 Oct 2006 02:52:55 +0200, Christopher Schmidt <[EMAIL PROTECTED]> wrote: > One of the things that I've been interested in for a while is an easy to > use map rectifier. There are a lot of maps -- historical maps > especially -- which are interesting on their own, but are far more > interesting if you mix them with other data. The reason I originally got > interested in this was for the idea of annotating OpenStreetMap > segments: take existing, out of copyright maps, georectify them against > known points, and use the resulting map to name streets. Obviously for > well-groomed areas of something like OpenStreetMap this would be of > limited benefit, but it does offer a new way for people who don't have a > GPS to contribute to poorly groomed or mapped areas of the OpenStreetMap > project. > > However, most of the existing options suffer in a variety of ways. The > primary way in which they suffer is not even a technical problem, it's a > well understood social problem: high quality map data is not free. No > free data means that desktop applications don't have much they can do: > unless you're Google or Microsoft, you can't afford the amount of data > you need to georeference maps for the whole world. > > Luckily, these days that data is made available from a number of > sources. Google Maps and Virtual Earth have moved into the realm of > providing free-to-view satellite data for the whole world, and that's > all you need for rectification. However, desktop applications like > GRASS and OSSIM don't have the ability to take advantage of this data: > the web nature of these tools makes taking advantage of them more > difficult for desktop applications, and there was no good way to use > these services to rectify a map. > > As part of working for MetaCarta, one of the things I get to do is work > on services which end up on MetaCarta Labs[1]. People who were at > Where 2.0 probably remember seeing MetaCarta up on stage presenting some > of the technology we host on Labs for public use. Finding places where a > significant gap in the tools available to the community exists and making > them available is one of the things that some of my time gets spent on. > > In an effort to help non-GIS professionals associate their images with > places in the real world, Schuyler Erle and I have developed a web-based > map rectification tool, which is available now for public use. The service > will allow you to upload an image, and using a reference map, you can > select ground control points -- points from the reference map which > match up to the uploaded image -- and then warp the image. You can use > any of a number of default base maps to reference against, or add your > own WMS or KaMap layers to the map and use them to find ground control > points. > > The service is available from http://labs.metacarta.com/rectifier/ . You > can see that there have been a number of interesting maps uploaded. > We've tried to make a service which is generally useful, including > providing WMS URLs to the warped imagery, providing the imagery for > download as GeoTIFFs, and allowing users to comment on the maps you > upload. > > I'm sure some of the people on this list have interesting maps that they > haven't had an oppourtunity to associate with the real world. > Personally, I've been having a lot of fun with the service: > georectifying imagery from MIT, from the 1930's to today, tourist maps > that I've taken snapshots of with a digital camera and uploading, and > historical maps from wikicommons. > > I'm not sure who else has a need for this type of tool, but if you have > a map image and would like to use it inside your OpenLayers > applications, this is one way to get started: upload the image, warp it > to fit, and drop it into place. No need to set up a server. Click a few > buttons and go. > > A quick getting started[2] guide is available, and I'd love to hear > feedback that anyone has on the service: what is broken, what is > missing, and what is nice about it. You can keep up with changes to the > service on the MetaCarta Labs weblog[3], which will mention any major > changes to the service. > > Check it out. I'd love to hear any thoughts you might have. > > Regards, > > [1] http://labs.metacarta.com/ > [2] http://labs.metacarta.com/rectifier/directions > [3] http://labs.metacarta.com/blog/ > -- Sam Critchley GeoPlaceSpace A2B Location-Based Search Engine http://www.a2b.cc Get our free GPS Software and search on the move Search for nearby sites - Add your own links - ping A2B from your weblog New - search and add links by street address! (US only) _______________________________________________ Geowanking mailing list [email protected] http://lists.burri.to/mailman/listinfo/geowanking
