Essential for visualizing Geographical Objects is a background map with world coordinates. The GIS Editor's Map mode offers a convenient way to create such a map, but it is restricted for the use of Google or OSM maps which are present in the web and are providing world coordinates. It would be nice to load scans of e.g. topographical or even historical maps into the working area and use them as background maps, but the problem is how to assign world coordinates to them.
The Adapt mode solves this in an easy way by executing the following steps. As a precondition a background map having world coordinates (e.g. a Google map) must be present which covers the area of interest of the new map to be referenced.
The adapted image has been transformed to fit into the current world coordinates
of the background map. Now the new map can be added to the sample list by pressing
the Add button
. When it is finally saved to disk by pressing
the Save button
, the new assigned world coordinates will be saved,
too, in an XML file with the same name (see
Save Samples).
Sometimes it is difficult to place the new map and the reference map side by side, because the window is too small, and zooming out would blur the details needed for setting the reference points. If the new map covers the background map, the reference points can be set anyway
Note: The Fill box must be checked to change the transparency of the new map. The background map's transparency cannot be changed.