Georeferencing a JPEG image as a new layer

Benjamin Wadham Gagnon's Avatar

Benjamin Wadham Gagnon

23 Aug, 2019 02:10 PM

Hi,
I'm trying to add a layer as a geospatial image JPEG.
I cannot see the image on my map when I click SET.
Therefore I can't georeference it.
I have read that there is a youtube video that explains this process.
Could someone please send me links to textual instructions and/or videos on how to georeference JPEG images as new layers in caltopo.
Thanks
Ben

  1. Support Staff 1 Posted by rmarcucci on 23 Aug, 2019 09:41 PM

    rmarcucci's Avatar

    Ben, If you send the link over I can take a look at it and see what's going on with it. It needs to be a direct static link to just the image itself, not part of an album page or the like. Here are the general instructions:

    1) Download the image, ideally in JPEG when available
    2) Convert it into a JPEG, if it's a TIFF or PDF
    3) Host that JPEG somewhere
    4) Add it as a geospatial image
    5) Align the points:
    Pick 2 points on the image that are easy to find on the basemap as well, ideally somewhat diagonally located from each other
    Rightclick georeference: mark point 1 on the image
    Rightclick georeference: mark point 2 on the image
    Turn opacity of the image to 0
    Rightclick georeference: mark latlong1 match the point on the basemap
    Rightclick georeference: mark latlong2 match the point on the basemap

    I hope this helps. The whole process is a bit clunky and it is on our radar to upgrade.

    Thank you for using CalTopo,
    Rom

  2. rmarcucci closed this discussion on 23 Aug, 2019 09:41 PM.

  3. Benjamin Wadham Gagnon re-opened this discussion on 26 Aug, 2019 01:40 PM

  4. 2 Posted by Benjamin Wadham... on 26 Aug, 2019 01:40 PM

    Benjamin Wadham Gagnon's Avatar

    Hi Rom,
    Thanks for the response.
    Here is the link to the image I am trying to upload to caltopo as a
    geospatial image.
    https://imgur.com/HXzlLB4

    When I try to upload to caltopo the following error message appears.
    This image exceeds the maximum size of 16777216 pixels. It will not
    display properly after the georeferencing dialog is closed.

    When I click ok on the CALTOPO SAYS box, only the white frame of the image
    appears. Therefore I cant georeference it.

    Any suggestions?
    Thank you very much!

    Ben

    Benjamin Wadham Gagnon
    Vertigo-Aventures.com <http://vertigo-aventures.com/>
    418-360-4153

  5. Support Staff 3 Posted by rmarcucci on 26 Aug, 2019 03:33 PM

    rmarcucci's Avatar

    Ben,

    If you aren't already using it, the direct link to the image is: https://i.imgur.com/HXzlLB4.jpg?2 You need to link to only the image itself where it is statically located. I had heard that imgur was doing away with this option, but it seems to work just fine for me via that link.

    Let me know if you're still having issues and thank you for using CalTopo,
    Rom

  6. rmarcucci closed this discussion on 26 Aug, 2019 03:33 PM.

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