B4J Question Read Geo-tag information from an image?

[Mashiane]

Hi there

Is there a way to read the geo-tag information of an image. I want to return lat, lng saved with an image?

Thanks

 

[Sandman]

You want the EXIF data.

https://www.b4x.com/android/forum/pages/results/?query=Exif

 

[Mashiane]

Thanks @Sandman, these seem to be useful, https://www.b4x.com/android/forum/threads/jpegutils-for-b4j.64072/#post-405450
and https://www.b4x.com/android/forum/t...-information-from-an-image.94697/#post-599372

will test and post my results...

 

[AHilton]

Be aware that there are lots of things to go wrong with trying to get Lat/Lon from images. Depending on your particular situation …

1) There are lots of places (such as custom EXIF meta tags) in the EXIF to put Lat/Lon. Standard libraries only check 1 or 2 places, at best. Just because a library or code doesn't find a Lat/Lon, doesn't mean it's not in there somewhere.

2) EXIF information can get stripped during some transmissions depending on where/how it's getting to where you can read it. Example, a picture sent from a phone through SMS can (but sometimes not, depending on image resizing or the whim of the cellular provider) get the EXIF data mangled or completely stripped off.

3) Some cameras don't put any Lat/Lon in the EXIF at all. Even when they say they do.

4) If a phone camera, GPS/Location has to be turned on. That's completely up to user control (= "good luck").

5) Sometimes there's bizarre GPS encoding going on by the camera to the EXIF data structure. It's not always as simple as just reading a decimal notation (or DMS) of a Latitude, for example.

Just a heads-up

 

[Harris]

Just a heads-up

That's why I use a table to gather extra info to store GPS (lat/lon), file name, date/time, device id, etc..).
I am in complete control rather than relying on the whims of disparate manufactures and their implementations of (whatever).

Using Camera through Intent is a prime example (photo taken as portrait shows as landscape when viewed).

Use your coding skills to satisfy your desires / app needs - or suffer later when users of different devices state it doesn't work.

 

[Mashiane]

I guess the best way is to then follow Harris methodology at least the level of comfort with that is better. Thanks a lot people. Added Lat Lng on my ABM app for any image uploads. Makes a sense.