Main menu > Imagery
Table of contents
This menu allows you to use various sources as a background layer in the MapView such as aerial imagery, cadastral plans or Maps rendered from OpenStreetMap data.
The Imagery menu has following entries:
|Imagery preferences||Opens the respective tab in the preferences. Imagery servers can be added and edited tehre.|
|Get Imagery Offset...||Opens a window, where you can download offsets of Imageries (optional from the Imagery Offset Database Plugin)|
|Store Imagery Offset...||Saves an offset in the offset database (optional from the Imagery Offset Database Plugin)|
|Mapillary|| ||Adds the mappilary layer. (optional from the Mapillary plugin)|
|New offset||Opens a window to adjust the offset of an Imagery.|
|Here will appear all Imageries, which are activated in the Imagery preferences. The following 4 entries are already activated from the beginning. Clicking on one of the entries will add the imagery to the Layer list. Adding an imagery is also illustrated at Introduction.|
|Bing aerial imagery|
|OpenStreetMap (Standard Black & White)|
|OpenStreetMap Carto (Standard layer)|
|Here will appear all non global imageries, which are available at the current center position and zoom of the MapView (only if they are not already listed above). This is determined by the bounds of the imagery, which you can see in the Imagery preferences.|
|Rectified Image...||For use with Metacarta's Map Rectifier. Clicking on this opens up a dialog box requesting an id. The id is obtained from either the page url or the WMS link (e.g. http://labs.metacarta.com/rectifier/rectify/73 - the id would be 73). Note if you are using these images for editing then you need to ensure the image, and its method of rectification, are free of any copyright issues.|
WMS basic troubleshooting
Things to try in case of problem.
No image appears, even after waiting a bit (message No tiles at this zoom level)
- Adjust zoom level so that the scale in the top left says ~300m.
Error: Could not load images from tile server
- The Imagery server address can be outdated.
- The Imagery server address can temporarily be not available.
Images at bad resolution
- Check if other aerial imageries are available. Make sure OSM has the permission to trace from it!
Exception occurred - red tiles
- This can mean the Imagery server is temporarily not available. Landsat and OpenAerialMap seem to be prone to periods of non-availability. Delete the WMS layer and try again 10 minutes later.
Error: bad parameters - red tiles
- Check that configuration -> projection is set to EPSG:4326 or Mercator.
- if you have non-ACSII symbols in the path to your plugin folder in Windows (e.g. cyrillic letters in your name in C:\Documents and Settings\your name\Application Data\JOSM\plugins), a possible solution is to change your name to an equivalent short filename. To find this open a command window and do dir /x "C:\Documents and Settings"
In its output the column to the left of your name should contain short version of your name, let it be for example 9335~1. Add a line to the batch file starting JOSM:
rem Contents of start_JOSM.cmd set APPDATA=C:\Documents and Settings\9335~1\Application Data start javaw -jar josm.jar
To reuse the tiles over JOSM sessions without having the reload them from the server, right click on the WMS layer and set a bookmark. During the next session, select the new WMS created by the bookmark in the WMS memu. Additionally, you may want to modify the following values in the preferences :
- cache.wmsplugin.expire -1 : this is a time in second until the tiles are invalidated. -1 means "never flush".
- cache.wmsplugin.maxsize 999999999 : maximal size of the cache (probably in MB)
Even though you have to download an area "manually", you can work offline using this technique.
Using a "Rectified Image"
Do not use copyrighted material, unless you have the right/permission to do so (see the Licensing section below)'''
Before you start with your own images, it might be a good idea to start with Landsat data so you'll learn how to work with these downloaded images.
To work with your own images in JOSM:
- upload your aerial image / scanned old map to either
- rectify it on their site so it "fits with reality"
- XXX - wait for the image to be processed?
- remember the metacarta id (look at the URL in your browser)
- in JOSM, load some openstreetmap data of the expected image area (to be in the right "clipping range")
- click on Rectified Image and enter the id in the upcoming dialog
If the "clipping range" was wrong, you might see just nothing. In this case zoom out and retry the download.
- Help/RemoteControlCommands#imagery -