2

In Picasa, in the Properties List, there is a property labeled "Unique Id".

In the Exif spec, there is a field called ImageUniqueId.

However, I have tried several Exif libraries/command line tools (e.g. exiftool), and none of them show ImageUniqueId.

So — is the Picasa "Unique ID" something that is stored in the image metadata, or is it something that Picasa computes on the fly?

If the latter, what is the algorithm that Picasa uses?

2

It is in the exif specification:

http://www.exiv2.org/tags.html

0xa420  42016   Photo   Exif.Photo.ImageUniqueID    Ascii   This tag indicates an identifier assigned uniquely to each image. It is recorded as an ASCII string equivalent to hexadecimal notation and 128-bit fixed length.

It is based on the timestamp and camera serial number, in an encryption manner.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.