Thursday 17 November 2011

Blogger removes GPS EXIF data from uploaded pictures

While writing my last post, I found out something interesting: Google Blogger strips out the GPS EXIF tags when you post it to your blog while leaving the rest intact.

Here's the exif data of the pic I posted yesterday - all of it identical to when it was taken.

 And here's the same pic uploaded to blogger and then downloaded again. Everything is the same except the GPS data, which is mysteriously missing. (The thumbnail is upside down, but I'm guessing that's because I used different programs to rotate them).


And just to make the situation more complex, I can go and have a look at the uploaded photos in picasa - and it shows the gps data as being intact!



So google doesn't modify the original at all, but will quietly rip out GPS data from any copies that are displayed publicly. This is a pretty useful safety feature. With it, I can just upload any picture without worrying that I'm giving away where I live or work.

It's confusing that I can't find this feature noted anywhere. It's the kind of subtle but important feature that shows a product has been carefully thought out and sets it apart from the rest, but neither the help documents nor my frantic googling found a single reference.

2 comments:

  1. Hey, I'm wanting to add a modification that allows the reader to click a picture for the EXIF info. Any tips?

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    Replies
    1. I don't know of any blogger modifications that do that, but there's a couple of ways around it.

      What I'd do:
      Link your pictures to an exif-displaying site that points back to the images themselves. I'd recommend http://regex.info/exif.cgi , since it takes the image location as a URL parameter which makes it damn easy to link to.

      Some other options:

      -You might be able to knock up a custom solution for the same thing. It should be possible to use pure javascript, but I haven't tested it. See http://www.nihilogic.dk/labs/exif/exif.js for an example that might work.

      -You could always just recommend your readers install an extension that does the work for them. It's the lazy option, but it might work out.
      Firefox: https://addons.mozilla.org/en-US/firefox/addon/exif-viewer/
      Chrome: https://chrome.google.com/webstore/detail/lplmljfembbkocngnlkkdgabpnfokmnl

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