How to export gallery metadata?

[skyrail]

I'd like to factory reset my Lollipop smartphone. But I have many pictures, downloaded from the web, shared by friends or taken with the stock camera, which I have tagged with my contact names, added google map geolocation, categories. I've done all of that within the native Android gallery app.

If I copy such images to another folder, the copy does not show the infos I previously added. It is the same if I make a copy on my laptop. So, is there any app to export those metadata, which are not supposedly included in the image file?

thanks.

 

[waqqas31]

Try using Samsung Kies 3 to do a full backup. It sounds like your best shot.

 

[skyrail]

I tried that, without any success, before exploring a programmatic solution with adb backup.
Infos I'm looking for is not exif data contained in photos, but tags, category, lib or gps location I can add to a picture from my android device. It might be any image from a camera or downloaded from the web.
I don't know where it is stored, either db file, xml ... sure it is not stored in the picture file.