Exif User Comment Edit

[Winston]

I have a software program that I am using that uses the exif user comment for the data field. I would like to edit the date and time in the user comment(see highlighted area on screenshot) to match the datetimeorignal tag without changing the rest of the comment. Can you tell me what I can do?

I have also attached one of the photos.

[Phil Harvey]

You can do this with the advance formatting feature and this rather complicated command:

exiftool "-usercomment<${usercomment;s/\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2} .M/$self->GetValue('DateTimeOriginal')/e}" -d "%Y-%m-%d %l:%M:%S %p" FILEorDIR

The only thing is that when you are done the UserComment will be formatted properly, whereas in the original it is written incorrectly (lucky ExifTool is so smart, or it wouldn't have been read it in the first place).

- Phil

[Winston]

I am not getting a date and time. See attached

[Winston]

It appears that it would also need to be formatted the same way, because the software no longer recognizes  the keywords in the comment.

[Phil Harvey]

I take it you figured out the problem resulting in the Screen.PNG output?  What was it?

If so, and the software requires an incorrectly written EXIF:UserComment, then you will need to override the ExifTool definition with a user-defined tag to be able to write it improperly like this.

- Phil

[Winston]

No, I didn't figure out the problem in the screen.png. It is just when the comment was changed the software looked to the file modify date for a date instead of the incorrectly written EXIF:UserComment.

But the software does not see the keywords anymore that are in the correctly written EXIF:UserComment.

[Winston]

Ok, I tried it again with exiftool 10.78 now. It just removed the date completely from the usercomment.

[StarGeek]

Error in the date format string, I think.

Try -d "%Y-%m-%d %H:%M:%S %p" instead.

[Phil Harvey]

I used %l instead of %H because it gives a 12-hour clock.  Didn't try to see if this works on Windows though. But even so, I don't understand the empty UserComment.

- Phil

[StarGeek]

Ah.  I guess it doesn't work on windows then and the whole thing gets blanked.

Code Select Expand

C:\>exiftool -DateTimeOriginal -DateTimeOriginal# -d "%Y-%m-%d %l:%M:%S %p" "Y:\!temp\!abr\2016-04-20 19-39-36.jpg"
Date/Time Original              :
Date/Time Original              : 2016:04:20 19:39:36

On Windows it looks like it needs to be %I:

Code Select Expand

C:\>exiftool -DateTimeOriginal -DateTimeOriginal# -d "%Y-%m-%d %I:%M:%S %p" "Y:\!temp\!abr\2016-04-20 19-39-36.jpg"
Date/Time Original              : 2016-04-20 07:39:36 PM
Date/Time Original              : 2016:04:20 19:39:36

[Phil Harvey]

You're right.  It should have been %I (capital I).  I mis-read my documentation, but an odd coincidence that %l (lower case L) worked for me.  However, it only gives a single digit for times less than 10, so it wasn't the right one to use anyway, especially since it doesn't work in Windows.

- Phil

[Winston]

Ok, I tested it and it did change the date now. But the software I am using does not see the keywords in the comment anymore. Apparently it need to have it in the same incorrect format that it was in before. Is there anyway to have exiftool keep it in the same format as before? I have attached a photo that was formatted by the software.

[Phil Harvey]

Yes.  As I mentioned, you need to create a user-defined tag to do this.  This config file will do it:

Code Select Expand

%Image::ExifTool::UserDefined = (
    'Image::ExifTool::Exif::Main' => {
        0x9286 => {
            Name => 'UserComment',
            Format => 'undef',
            Writable => 'undef',
        },
    },
);
1; #end

- Phil

[Winston]

I am not sure how to use the config file. Do you have somewhere I can learn how to use it?

[Phil Harvey]

The sample config file contains instructions and examples.

Also, you could search the Appliction documentation for "config".

- Phil