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I need such a database of smartphones cameras:

  • Each smartphone in the database must have the focal length of BOTH the front camera (typically used for selfies) and the back camera (typically used for landscapes/etc, also called rear camera)
  • The most popular smartphones should be covered. My goal is to cover like 70% of the current world users, the more the better. By the way, many users have rather old smartphones.
  • Each smartphone should be identified with some identifier that can be found in the EXIF of the photos it takes. Other metadata about the phone is not necessary (I can remove what I don't need).
  • Open data: freely reusable and embeddable into Apache2-licensed software
  • If the DB doesn't exist, and if you use an open photo repo, you can estimate focal length from EXIF tags phototour.cs.washington.edu/focal.html – philshem Nov 30 '18 at 13:58
  • @philshem: Thanks! Actually I would be OK with a database that gives aperture (instead of focal length). Using the pictures at commons.wikimedia.org/wiki/Commons:Mobile_app as a sample, it seems that most have both "F number" and "focal length" in their EXIF. – Nicolas Raoul Dec 1 '18 at 15:03
  • @philshem: Using an open photo repo (like Wikimedia Commons) is a great idea. But it requires that I know, for each picture, without looking at the EXIF, whether it was taking using the front or back camera, right? Also, I guess open photo repos have almost no pictures taken with the front camera, because they tend to have policies against selfies :-) – Nicolas Raoul Dec 1 '18 at 15:06
  • I think once you have a statistical sample per phone model (N>4 or so), you can smartly split the front and back camera based on the photo metadata. But yes, good point about the front camera and selfies. Maybe you can use Flickr flickr.com/photos/aists/29961732803/meta or similar site for photographers, since they are usually happy to share EXIF, and those sites are less likely to remove metadata. – philshem Dec 2 '18 at 14:00
  • Searching for "selfie" on Flickr leads to some smartphone-taken selfies such as flickr.com/photos/142783908@N04/25235493687 (Android Nexus 6P). Unfortunately Flickr is very Western-centric, the smartphone app is not available in all countries (130 new countries were added in 2017), which means it probably has no selfies for Chinese and Indian models for instance. – Nicolas Raoul Dec 3 '18 at 10:56

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