Re: [gthumb-list] Display IPTC comment in the sidebar

[John Burke <johnburke firemail cc>]

On giu 06  9:00, grubernd wrote:
> welcome to metadata hell. =)

I guessed it was such a mess :).

> i would try to write to IPTC:Caption-Abstract with your metadata tools.
> gthumb picks that up without a problem.

So far, I tried with this one. More details below.

> also XMP:Description should be no problem, just like EXIF:UserComment.
>
> and yes, gthumb writes the comment to those three fields, because they are
> the ones that get used by most programs. three standards.

Ok, so this is expected.

> you can not add new fields, but you can see more by switching to the
> detailed view with the selector buttons at the bottom of the sidebar.

Yes, I had noticed that button.

> in more than 20 years of fighting with and against all kinds of image
> metadata, i never came across wrjpgcom until now.

Oh, this is very curious. Being an absolute noob, after some search I
found this pdf guide:

https://wiki.linux-ottawa.org/lib/exe/fetch.php?media=wiki:scanjpgwoes.pdf

It suggests using `wrjpgcom' and `mapivi' (between others).
I was guessing the added comment is in some IPTC field because of this
sentence, in the pdf:

``mapivi and wrjpgcom put the information in the (IPTC) field Comments''
(pag. 5).

Maybe this is uncorrect, even because `mapivi' itself lists the comments
added with `wrjpgcom' in the EXIF section.

This was my source, but there is no problem for me to switch to more
"standard" tools like the ones you suggest:

> my take: switch to one of the standard tools for mangling image-metadata ..
> exiftool or exiv2. maybe not as simple, but more consistent and compatible
> with others.

I tried `exiv2' to modify `IPTC:Caption-Abstract'. At a first glance,
your notation `Caption-Abstract' slightly confused me, because the field
you mention seems to be

Iptc.Application2.Caption

in https://www.exiv2.org/iptc.html. But this is all right. In fact, I
added the comment this way:

exiv2 "-Mset Iptc.Application2.Caption Some comment" image.jpg

and the result is exactly what you suggested:

$ exiftool image.jpg
[...]
X Resolution                    : 1
Y Resolution                    : 1
Current IPTC Digest             : af9b535dc81a8e9c83bb3b774eb45c1c
Caption-Abstract                : Some comment
Image Width                     : 2048
Image Height                    : 1365
[...]

And, above all, `Some comment' is automatically shown in the
bottom-right angle of the `gthumb' window, as desired.
Thank you so much for your very detailed answer and for all your
suggestions!
Bye,

John