GeoPortOst offers, if possible, references to sources and contexts to maps. Contexts can be found in the right menu bar of the Geoportal under Kontext / Context. This additional information is suitable for a better understanding of maps and the process of map making. GeoPortOst uses the software Recogito for contextualization.
Open your map in the Geoportal. In the menu bar on the right you will find the Annotation button under Tools. By clicking the button you can open the map image in Recogito. Recogito has a zoomable view so you can navigate even highest-resolution images easily. Zoom using your mousewheel or the + - buttons in the upper right corner.
In the toolbar, there is a drop-down menu where you can switch between Recogito's different selection modes: Point, Rectangle, Tilted or Linked Box. Select Point and create an annotation by clicking somewhere in your image. Switch back to Move to resume standard image navigation.
You can annotate an area using Rectangle. Pick the Rectangle tool. Click once to select the starting corner of the area. Then click again for the opposite corner.
The Tilted Box tool may take a bit more practice: select it from the menu. Click the mouse button once to start drawing the baseline of the box. Click again to set the end of the baseline. Move the mouse to define the height of the box, and click when you are happy with the height.
The Linked Box is a modified version of the Tilted Box, designed specifically for maps containing symbols and labels.
Click once to mark the symbol, then continue to annotate the label as you would with the Tilted Box: click to start the baseline, click again to end it, click once more to set the height. You can modify all points afterwards, by clicking and dragging them.
If you want to identify a place, click on Place in the annotation editor. Recogito will attempt to provide an automatic suggestion from Geonames. You can either confirm this suggestion, or try to find a better match in the search. If you can't find a suitable match, you also have the option to flag this reference, as an indication that no suitable match was available.
The annotations can be exported in different formats (CSV, RDF, GeoJSON, KML) and remain saved for further processing.