[josm-dev] Problems creating TileSource for ArcGIS REST API

[Ian Dees]

Don't reproject your coordinates to Virginia, just tell ArcGIS that your
request bounding box is in Spherical Mercator projection by passing in a
projection id of 102113.

On Thu, Feb 17, 2011 at 10:04 AM, Josh Doe <josh at joshdoe.com> wrote:

> As I've mentioned on this list, I'm interested in support in JOSM for
> the ArcGIS REST API [1], as my location (Virginia, USA [2]) has very
> good quality (1ft resolution, off-leaf), public domain imagery, but is
> only available via that API.
>
> Ian Dees suggested I extend AbstractOsmTileSource and convert the
> requested tile x/y/zoom to coordinates, and then use the export
> interface of Arc GIS REST [3] to request the tile. I've implemented
> this, and I'm happy to see that the imagery lines up correctly,
> however there are gaps between vertical tiles, which you can see in
> this image [4]. You can view the code here [5].
>
> Why might this be happening? I'm guessing it has something to do with
> projection differences, but I don't really know.
>
> The Virginia ArcGIS REST server uses the Virginia LCC projection, so I
> first convert the tile x/y/zoom to WGS84 lat/lon corners, convert
> those to Virginia LCC using the Proj4J plugin [6], then submit the URL
> to the server.
>
> I know this should be a temporary solution anyways, as I should be
> using the tile cache provided by the server, however it seems more
> difficult to implement considering the tiling scheme is completely
> different than the mercator system used by TMS, so I'd need to do more
> than just create a TileSource, but rather assumptions about resolution
> and zoom levels must be changed in other JOSM code.
>
> Any thoughts would be appreciated, thanks!
> -Josh
>
> [1]: http://resources.esri.com/help/9.3/arcgisserver/apis/rest/index.html
> [2]:
> http://wiki.openstreetmap.org/wiki/Virginia#2006.2F2007_VBMP_Orthoimagery
> [3]: http://resources.esri.com/help/9.3/arcgisserver/apis/rest/export.html
> [4]: http://postimage.org/image/7g16nd6s/
> [5]: http://java.pastecode.com/2183
> [6]: http://wiki.openstreetmap.org/wiki/JOSM/Plugins/Proj4J
>
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