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I have a set of images like this one attached below: distribution of a give species

I would like to georeference the image/map in order to overlay it with Google Satellite images and then produce some polygons in a GIS. Unfortunately, when I try this operation (through QGIS' plugin 'Georeferencer'), I obtain maps with strong distorsion at borders. For example, it is impossible to overlay the countries of Oceania (which is the main focus of my study).

I think that depends (but I'm not sure) from projections systems, which affect the borders of a map.

Any idea to solve this trouble?

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    have you tried playing with input CRS? This looks kind of like a Robinson projection that has just been turned into a rectangle along the edges. Also, if Oceania is your main area of interest, start with you anchor points down there and work around the edges to try to match the full extent first, then work on the inner anchor points.
    – Lovette
    Dec 18, 2017 at 21:08
  • Great! You resolved all my troubles! Tankk you! I confirm: the map is in Robinson projection!
    – Marco
    Dec 18, 2017 at 22:08
  • great, i'll make an answer if you want to accept
    – Lovette
    Dec 18, 2017 at 22:55

1 Answer 1

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Try playing with the input CRS. This looks kind of like a Robinson projection that has just been turned into a rectangle along the edges.

Also, if Oceania is your main area of interest, start with you anchor points down there and work around the edges to try to match the full extent first, then work on the inner anchor points.

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