Exporting map as georeferenced image

Question

I am using OpenLayers to create a map where I can Zoom and export the view (Following this exemple https://openlayers.org/en/latest/examples/export-map.html) This works fine, but what I need is a georeferenced image (ecw, geotiff) that users can use later on QGIS...

Does anyone knows how can I do this ?

Answer 1

You can try the demo I've made.

It creates a zip with png files, associated pngw (world file) and prj files in a single zip when exporting.

The important part is for writing the pngw with below excerpt.

  var currentResolution = view.getResolution();
  var currentExtent = view.calculateExtent(); // Return [minx, miny, maxx, maxy]
  var pngwContent = [
    currentResolution,
    0,
    0,
    -currentResolution,
    currentExtent[0] + currentResolution / 0.5,
    currentExtent[3] - currentResolution / 0.5
  ].join('\n');

Then, you open it in QGIS (It's possible without unzipping). It will ask you to choose the projection (in this demo, with EPSG code 3857)

The quick result I got for an overview in QGIS using Wikimedia base maps.