Using geospatial images from local drive or Google Drive

jsassojr's Avatar


01 Nov, 2018 08:04 PM

I want to leverage caltopo's feature of adding a geospatial image layer but it requires one to specify the URL of the image (a JPEG file). My problem is that such an image will come from either my local disk or a network drive, OR from my Google Drive. In the case of the latter, I made the file shareable and accessible to all, then entered the shareable link in caltopo, but when I click Set, just a rectangular outline appears, but no image. Mind you, the shareable link has no .jpg extension

How can I get caltopo to access images from where I have them stored? These are portions of images we take a snapshot of from a website (e.g. a parcel of land in a county's GIS viewer), and want to overlay into Caltopo for further analysis. Specifying a URL seems very limiting. Thanks!


  1. Support Staff 1 Posted by matt on 05 Nov, 2018 04:34 AM

    matt's Avatar

    It requires a little more work / knowledge to get set up, but the best option is probably an Amazon S3 bucket setup for website hosting. You do have to sign up with a credit card and pay but it should be trivially small, ie on the order of $1 / month.

  2. 2 Posted by craig.billie on 11 Nov, 2018 03:13 PM

    craig.billie's Avatar

    I've run into the same issue trying to use things from google drive. I found one of the maps I wanted to overlay on a public FB page, and when I used that URL, the image did show up on my underlying map. But... nothing else in the "Add Geospatial Image" dialog box seems to work! Toggling the opacity does nothing, and right clicking on the map to set a georeference point only brings up the original map options of new, measure and point info. Has anybody else run into this? Nothing I've tried gets me past just getting the image to appear. Using Chrome but I've also tried it in IE with the same results.

  3. 3 Posted by John D on 25 Nov, 2018 10:42 PM

    John D's Avatar

    Or option b:
        install python and SimpleHTTPServer script in your PC
    You can then load files images for georeferencing from local drive and dirctory where you are running python -m SimpleHTTPServer:8000

    In SARTopo you would say http://localhost:8000/myjpg.jpg and the image will load

  4. 4 Posted by John D on 25 Nov, 2018 11:54 PM

    John D's Avatar

    Update: Error

    While the image will load, and even though it exports correctly in a json file,
    the image does not show after being saved.

    There is likely an internal security mechanism in the browser that does not allow loading a file from the local drive by a remote website - even if it is being served by http in the local machine.

    I tried with localhost, and the server name as the server. None of the above works.

    Sorry for confusion above.

  5. System closed this discussion on 02 Oct, 2019 04:24 PM.

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