# Problem with resolution of exported image

I want to make a map (of Germany) with certain positions marked. This is just a MWE, in fact there are much more positions. What I did:

   positions = {{47.5, 11.08}, {47.57, 8.03}, {47.6,
8.13}, {47.65, 7.6}, {47.65, 7.78}, {47.66, 9.48}, {47.7,
10.32}, {47.73, 12.1}, {47.77, 9.72}, {47.77, 11.62}}


and

marker = Graphics[{Blue, PointSize[0.4], Point[{0, 0}]}];


then (this - Entity - is keyed in manually because of the complicated structure of the Entity in this command when done via copy and paste)

    map = GeoGraphics[{GeoStyling["StreetMap"],
Polygon[Entity["Country","Germany"]],
GeoZoomLevel -> 9,
GeoMarker[positions, marker]
},
GeoBackground -> None, ImageSize -> 2000]


If I do so the map looks fine:

If I export the image:

Export["germany-04.JPG", map, "JPG"];


and re-import the image it is much more coarse. I tried with something like

Export["germany-04.JPG", map, "JPG", ImageResolution-> 300];


and explicit ImageSize, but I never get close to the the original resolution (same with export formats like SVG, EPS, PNG. If I copy the map (as graphics) and try to import in Photoshop.... Mathematica crashes (??).

My system: MacOS 10.13.5, Mathematica 11.3.0, my goal is to get an exported image good for print.

• JPEG ("JPG") image files has lossy compression, and Mathematica uses a "CompressionLevel" of 0.25 by default. – rhermans Jun 26 '18 at 7:43
• @rhermans: JPG was just an example here - same problems with SVG, WMF, PNG etc. Picture dimensions are approx. 2000x2700, so this is too few to get the names of towns readable in a "pixel-environment". It seems that PDF is much better there. – mgamer Jun 26 '18 at 20:35

## 1 Answer

Save it as pdf, then open in Acrobat and the resolution seems to be preserved.

Export["germany-04.pdf", map, "PDF"];

The pdf file is about 40 MB, so that may explain the instability when trying to copy/paste.