Creating/Adding MetaData to JPGs

[drmiller]

I've got thousands of JPGs after having 4x6 prints scanned professionally. Apparently, these JPGs do not have ANY metadata (EXIF or IPTC???). All of the EXIF adjusting utilities (Mac) that I found cannot add/create metadata but can only modify/edit the metadata that is already there in the binary. Many of these JPGs have dates printed on them (from my older non-digital camera). When I try to adjust the dates for the JPGs in iPhoto or Picasa (for the Mac) I can change the create/photo taken date (not easily, and not for thousands at a time) but still nothing shows up in the EXIF data (even though they sort correctly by date and there is no obvious file date modifications, create or modified).

What I'd like to do is to add a blank (or relatively blank) EXIF (or IPTC or whatever) to each of these JPGs so I can use other photo utility programs to display each JPG from a folder, visually read the date (if there is a date), edit the photo taken date (or original) that I've read, and go on to the next picture.

So, what is the best approach to do this? I would think batch adding metadata to each JPG would be a start. Can ExifTool do this?

Also, I'm a bit of a Cocoa programmer. Would the ExifTool APIs let me create a program to do what I want (or if you know an existing program that does this, please let me know)?

Thanks.

[Phil Harvey]

I find it surprising that the other utilities can not add EXIF (or whatever) metadata to an image.  You can do this easily with exiftool.  For example:

exiftool -exif:datetimeoriginal="0000:00:00 00:00:00" DIR

will write EXIF DateTimeOriginal to all images in directory DIR, creating the EXIF segment if necessary.

You can also do this via the API, but it sounds like the distributed exiftool script already does what you want it shouldn't be necessary to write your own script.

- Phil

[drmiller]

Thanks for the quick reply. After further reading (here and elsewhere), should I be writing a MWG (XMP?) header instead of EXIF metadata (for date-time-original)? And do you know if one or the other works better with Mac apps (like iPhoto or Picasa)?

[Phil Harvey]

The MWG specification deals with keeping EXIF, IPTC and XMP all synchronized.  If you write only EXIF you don't need to worry about the synchronization, but if you want to write the others as well then you can use the ExifTool MWG tags to make this simpler.

I hope this makes some sense.  I know metadata can be confusing.

See the MWG Tag Name documentation for more gory details.

- Phil

[drmiller]

Thanks again. In the meantime, I've found an app for the Mac, PhotoLinker, which appears to do everything I want (esp. view picture and change datetimeoriginal) but still having some issues with iPhoto after the change. They use ExifTool, so I imagine you know them.