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Due to customization wishes I created a map in Adobe Illustrator which means my .tiff file has no metadata like CRS, extent etc. when I export it.

To manually set the spatial extent I would need an option like it used to be in the properties menu (How to edit a vector layer extent?) but it was removed.

I can't find a similar option in a newer QGIS version (3.14 or higher) for raster data. Though the menu to set the extent metadata is still there it is only for documentation purpose and does not actually change the size of the map on the canvas. If you know how to achieve this while keeping RGB values, please help me.

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    Have you tried the raster calculator? You can set a new extent in the raster calculator.
    – Nil
    Jan 6 at 17:55
  • @Nil Thank you for your response - I did not know about this possibility. Other than I expected my image appeared split as 3 available bands when opening the raster calculator. I processed each of them with the new coordinate data entered. It added a new layer with the correct coordinates but the image itself was gone. Instead it was being rendered as a single band gradient from a minimum value of 1.79769e+308 to a maximum of the same value (= nothing is visible). Is pre-editing necessary to get results? Also, it seems that this method only returns gray-scale images.
    – nichomeso
    Jan 6 at 18:45
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If your question is "How can I import a raster image without extent/CRS information to QGIS so that it appears in the right place", than the answer is: georeference the image. For this, you can use Georeferencer.

You load your picture to the Georeferencer window, set a few control points on your raster and select the correspondent coordinates (in the CRS you want the map to appear). You can either fill in the values manually or selecting them by clicking on a basemap. If your map is in a known CRS, it might be enough to define three, four control points, even the 4 corners of the image that correspond to the extent of the map.

If the CRS is not known, several more points are needed for good results.

See this answer here for which transformation settings to use: https://gis.stackexchange.com/a/226948/88814. For a first try, Polynomial 2 is a good choice.

There are many tutorial out there for georeferencinng. A good one includes the video tutorial by Klas Karlsson.

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