exiftool manpage not complete

[gregoa]

We have the following bug reported to the Debian package of
Image-ExifTool, c.f. https://bugs.debian.org/1051341

It doesn't seem to be a bug in the packaging, so you may want to take
a look. Thanks!

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Package: libimage-exiftool-perl
Version: 12.65+dfsg-1
Severity: wishlist

I had an image where I knew the GPS coordinates where it was taken, but
I did not have a GPX log. Surely it should be possible to tag a single
image with a given coordinate? Reading the manpage it looked like I
would have to fake a GPX log...

A bit of googling led me to
https://exiftool.org/forum/index.php?topic=9415.msg48698#msg48698 wher
it was shown that you can do:
exiftool testcoord.jpg -gpslatitude=40.25090199998273 -gpslongitude=75.13265800002499 -gpslatituderef=N -gpslongituderef=W
i.e. directly enter the coordinates on the command line.
This works!
However hint at all about this functionality in any documentation.
Perhaps this can be added? Even if only as an extra example in the
geotagging examples.

Thanks,
Paul

-- System Information:
Debian Release: 12.0
  APT prefers stable
  APT policy: (800, 'stable'), (500, 'stable-updates'), (500, 'stable-security'), (500, 'unstable'), (500, 'oldstable'), (100, 'bookworm-fasttrack'), (100, 'bookworm-backports-staging')
Architecture: amd64 (x86_64)

Kernel: Linux 6.1.0-10-amd64 (SMP w/16 CPU threads; PREEMPT)
Kernel taint flags: TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_IE.UTF-8, LC_CTYPE=en_IE.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: sysvinit (via /sbin/init)
LSM: AppArmor: enabled

Versions of packages libimage-exiftool-perl depends on:
ii  perl  5.36.0-7

Versions of packages libimage-exiftool-perl recommends:
ii  libarchive-zip-perl         1.68-1
pn  libcompress-raw-lzma-perl   <none>
pn  libio-compress-brotli-perl  <none>
ii  libunicode-linebreak-perl   0.0.20190101-1+b5

Versions of packages libimage-exiftool-perl suggests:
ii  libposix-strptime-perl  0.13-2+b1

-- no debconf information

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Thanks for considering,
gregor herrmann,
Debian Perl Group

[StarGeekSpaceNerd]

Phil is currently away until next week at least, but I will say this.

These are only four tags out of the 26,990 different metadata tags that Exiftool can currently read, many thousands of which are writable. Exiftool documentation tells how to use exiftool. It's not there to document all of these thousands of different pieces of metadata. For that, we must refer to the various standards, such as the IPTC Photo Metadata Standard, the EXIF standard, the EXIF for XMP standard, etc, etc. That's doesn't even cover tags that are proprietary to the varies camera models a.k.a. MakerNotes, to specific programs such as ACDSee or DigiKam, or many other extremely obscure schemas. Even Victoria's Secret, the lingerie company, has their own schema that they put in their images.

The Exiftool Forums tend to be very casual and try to be helpful. We don't tell people to do a search first or RTFM. Metadata is an absolute hellscape and many people don't even know what terms they should be searching for.

So it is quite unlikely that Phil will add an exception in the documentation for these four tags. The documentation is extensive as it is.

[boardhead]

Thanks for this. It is true that the documentation doesn't provide an example of how to write known GPS coordinates to a file, but as StarGeek says, there are too many possible tags to have examples of how to write them all.

However, I will add a note in the -geotag examples section to make it clear that this is for geotagging from log files, and that geotagging with known coordinates is done by writing the GPS tags directly.

• Phil

[gregoa]

Thanks Phil!

[gregoa]

So, I guess, that's

-ExifTool implements geotagging via 3 special tags: Geotag (which for
-convenience is also implemented as an exiftool option), Geosync and Geotime.
-The examples below highlight some geotagging features.  See
-L<https://exiftool.org/geotag.html> for additional documentation.
+ExifTool implements geotagging from GPS log files via 3 special tags: Geotag
+(which for convenience is also implemented as an exiftool option), Geosync
+and Geotime. The examples below highlight some geotagging features.  See
+L<https://exiftool.org/geotag.html> for additional documentation.  (Note
+that geotagging from known GPS coordinates is done by writing the
+L<GPS tags|Image::ExifTool::TagNames/GPS Tags> directly rather than using
+the B<-geotag> option.)

in 12.66 or 12.67 which is not mentioned in Changes?

[boardhead]

Hi Greg, Correct. Documentation changes don't appear in the version history. - Phil

…

On Sep 28, 2023, at 7:45 PM, gregor herrmann ***@***.***> wrote: So, I guess, that's -ExifTool implements geotagging via 3 special tags: Geotag (which for -convenience is also implemented as an exiftool option), Geosync and Geotime. -The examples below highlight some geotagging features. See -L<https://exiftool.org/geotag.html> for additional documentation. +ExifTool implements geotagging from GPS log files via 3 special tags: Geotag +(which for convenience is also implemented as an exiftool option), Geosync +and Geotime. The examples below highlight some geotagging features. See +L<https://exiftool.org/geotag.html> for additional documentation. (Note +that geotagging from known GPS coordinates is done by writing the +L<GPS tags|Image::ExifTool::TagNames/GPS Tags> directly rather than using +the B<-geotag> option.) in 12.66 or 12.67 which is not mentioned in Changes? — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.