4 ms·
The logic doesn't hold up. I uploaded a bunch of photos taken in Christchurch, New Zealand. The pics were over two years old and I now live in the UK and upload
by Peroni 15y ago
The logic doesn't hold up. I uploaded a bunch of photos taken in Christchurch, New Zealand. The pics were over two years old and I now live in the UK and uploaded them from here. The photos were also taken on a cheap, point & shoot camera, not a smartphone.
- phpnode 15y agoAlso, does the location info purely say "Christchurch, New Zealand" or is it more granular? I'm guessing that when facebook only has sparse information about your location, as in your case, it "zooms out" to the city, state, country etc, but the more information it can collate, the more accurate the suggestion it gives is.
- phpnode 15y agobut did you use facebook at all when you were in new zealand?
- Peroni 15y agoIndeed but when I posted the pics it was 2 years later from a totally different continent and no reference to the location on the photos.
- phpnode 15y agoright, but assuming the timestamp is on the photos, facebook still knows where you were at the time they were taken. The time you upload them is immaterial
- pud 15y agoIn your opinion, how would Facebook know your location if you never logged in from a GPS-enabled smart phone? (and never approved an HTML5 geo permission request on your laptop). That's the interesting question here.
- phpnode 15y agowell they can do a best guess based on the location of your IP, even if you only sign into facebook once while you're travelling. The really interesting question is: can they do this even if you have not signed into facebook at all on your travels, or for totally new accounts with no location history at all. If they can, then they must be doing image recognition in some way. Perhaps someone who has more time / energy than me could try this by creating a new account and uploading some photos of recognisable objects (but without exif geo data).
- pbhjpbhj 15y agoFacebook knows more about me than I do. I'd be interested in their history file of my location.
- msbarnett 15y ago> In your opinion, how would Facebook know your location if you never logged in from a GPS-enabled smart phone? (and never approved an HTML5 geo permission request on your laptop). No real trick to that; if the user signs in from an IP leased to a Christchurch, NZ ISP on March 5th, 2007, then it's a safe bet that any photos taken that day were taken near Christchurch (and you get date taken from the EXIF data of virtually every camera on the planet).
- jfoster 15y agoWhen you were in NZ: [hh:mm dd/mm/yyyy, nz.ip.address] => [hh:mm dd/mm/yyyy, location] When you uploaded the photos: [hh:mm dd/mm/yyyy, photo] + above data => [photo, location]
- JonnieCache 15y agoGuess: your friends also took pictures of the same events from similar angles and uploaded them, fb worked out their location from one of the other suggested methods, and then matched it to your photos through simple computer vision algorithms. Or, you used facebook at some point while in that city, facebook recognised that your photo was of a baby just born, by comparing it with the millions of other photos tagged with "OMG MY BABY IS BEING BORN!," it knows that babies are born in hospitals, and it knows that there is only one hospital in that city, so it guesses that the photo was taken in that hospital.
- terhechte 15y agoIt doesn't need to be taken on a smartphone. It's sufficient to open facebook on a smartphone only once (app or web) in roughly the same timeframe that the picture was taken. It can then look where one has been in the timeframe when the picture was taken by comparing the picture timestamp with the list of checkin ip addresses, and do a geolookup of the ip address against a location database.