I'm exporting a map to a PNG file in QGIS 3.10.4 via
Project > Import/Export > Export Map to Image. In the dialog that shows up, I can select the extent (exported area), scale, resolution (DPI), and image size (in pixels). Obviously those are related, and changing them completely independently is not possible. QGIS automatically propagates changes made for one quantity to others so that the values stay consistent:
- If I change the extent, the image size is adjusted
- If I change the scale, the extent is adjusted
- If I change the resolution, the image size is adjusted
- If I change the image size, the extent is adjusted
My goal is to create an export with a given extent, scale, and resolution (and the image size necessary to achieve that). Given the automatism described above, that's rather cumbersome to achieve: I'd like to take the extent of a given layer (the dialog includes an option for that), but this automatically sets the scale to that of the current view (I think?). When I then set the scale to my desired value, this automatically changes the extent.
My current workaround is to first set the extent to that of the desired layer, writing down the values, setting the scale, and then re-entering the desired extent. Surely there must be an easier way?