Using EXIF tags to remember External Viewer image rotation?

Sorry, if this has been discussed before.

Is there a way to edit EXIF tags for jpg images created with a DigiCam?
[ul]I am aware that lister columns let you show EXIF information, and it is also possible to use this info in more complex renaming operations. But editing is still on the todo list?[/ul]
If so...

Request: I would love to have an option under Prefs - Viewer - Standalone Viewer like "Save JPG's rotation EXIF tag whenever the image is rotated (in real time)".
[ul]This would let me fix the rotation of my images on-the-fly, without actually changing the data (yes, lossless rotation for JPGs would also be possible, but IMO that is overkill). If I understand the EXIF tags correctly they are similar to mp3 tags, so updating the info for the rotation angle in real time should be possible?[/ul]

Question: For now, is there some manual way to change/set the rotation EXIF tag for a list of JPG files?

Note: My Sony Cybershot camera does not have a rotation EXIF tag (should that make a difference).

Thanks.

Opus does do lossless JPEG rotation where possible, by the way. (Only thing is I don't think there's an easy way to know if a given file will be rotated losslessly or not.)

I think you can use a command-line tool like EXIFTool to create buttons/hotkeys in Opus which edit the EXIF rotation tags which in turn should make Opus display the thumbnails & images rotated in the same way (assuming those options are on in Opus):

sno.phy.queensu.ca/~phil/exiftool/

Thanks for the link.

I had thought Opus already had some internal command to let you manipulate EXIF tags. Probably on Jon's todo :slight_smile:

PhotoMe is the most convenient EXIF editor I have come across.

Regards, AB

First off, thanks for the link...

Alas that tool, though probably the most over-featured tool I have ever seen, is alas quite counter intuitive.

The rotation via EXIF field only seems to work at random, and there is no way to replace or change fields for a batch of image files :frowning:. (Side note: Tag&Rename for MP3 files does a far better job when it comes to editing tags.)

Since it calls itself an editor, I wonder how much editing the users actually do with it.

I may really have to go back to the console command, mentioned above, and create a Opus button for it.

I want to thank everyone for the feedback... but looking into the matter of EXIF tags seems to be a lot more trouble than it is worth.

Testing the lossless rotation for JPG Digicam images, provided by Opus' internal Convert Image tool seems to work really well, so I have now started to actually rotate the images instead of trying to fiddle with EXIF tags.

For those folks interested here is the code I used for the 2 new rotation buttons I created:

[code]Label: Rotate Left (90°CCW) Replace\tCtrl+F11
Tip: Rotate a JPG image by 90° CCW using lossless convertion, overwrite original file.
Hotkey: Ctrl + F11
Function: Image CONVERT ROTATE=270 HERE REPLACE PRESERVEDATE

Icon: rotateleft[/code]
and

[code]Label: Rotate Right (90°CW) Replace\tCtrl+F12
Tip: Rotate a JPG image by 90° CW using lossless convertion, overwrite original file.
Hotkey: Ctrl + F12
Function: Image CONVERT ROTATE=90 HERE REPLACE PRESERVEDATE

Icon: rotateright[/code]

Simply select the images you need to rotate, I suggest doing so in Thumbnails mode, then either press Ctrl+F11 or Ctrl+F12, to rotate the image left or right. The original image file is overwritten in the source lister. The thumbnails are updated in real, time so you can check right away if you rotated the image correctly.

Hope that helps.

Glad to hear you found an answer to your problem. :smiley:

FWIW with the exception of the three date fields, I don't think EXIF tags are intended to be edited. EXIF is generated by the camera and I think the idea is nothing should ever be allowed to touch that metadata again (with the possible exception of the dates/times). There is also a comment field available in EXIF which can be edited but it's rarely used by most folks since IPTC and xmp are more suitable for that.

True enough.

Ideally the Orientation EXIF field (rotation angle) would have been set by the camera, and would require no editing at all. Alas my camera is too old to have such info available.

I found it marginally unnerving that modern DigiCams should provide so much info, especially the Longitude and Latitude info would make it possible to exactly locate were "private" pictures have been taken. I wonder how many folks are aware that they may be giving out a lot more info than they intended. I am still not certain if EXIF fields still exist even after editing the the image, i.e. cropping and then re-saving?

Anyway, looking through the default Toolbars I noted that there already is a Rotate Left (and right) button, only it does not use the CONVERT parameter, as opposed to what I posted:

Does anyone know if the using the CONVERT parameter in a "hopefully" lossless rotation does any harm?

You don't get the GPS information unless a) your camera has a GPS module, which is quite rare even these days, and in which case you would have to enable it (and you would definitely know about it because it would eat your batteries like mad) or b) you have manually tagged them after the fact using a GPS log of some sort.

As a possible suggestion - should Opus go that path - a function that deletes all the EXIF information in JPGs might be of interest to some folks.

Several image processing programs (Photoshop and Lightroom to name a couple) provide easy ways to strip out the metadata in images. Or if you happen to use ExifTool as mentioned by Leo earlier in this thread you could do it to the images you have selected in Opus by using the following command in a button:

exiftool -all= {f}

When stripping metadata it's highly recommended that you make copies of the originals first. Because once the metadata is gone, it's gone forever.