editing metadata of a jp2 file on mac

[pietro]

Hi!

I want to add some metadata to jp2 produced from tif files using magick.

There are several files in a folder, so I do in a bash script  something like this

exiftool -v1 -ext jp2 DIR -r -Artist='Surname, name' -UserComment='My comment' -overwrite_original

All runs ok.
I then check that the metadata is there with exiftool.

exiftool -a -G1 -s DIR/FILE.jp2

among others, I see the following and I am happy
[IFD0]          Artist                          : Surname, name
[ExifIFD]       UserComment                     : My comment

All is well, metadata has been updated. But... I need these metadata to be visible for users, and, on my mac, I cannot get to see any of those new metadata with any tool...

Is this a problem in how I understand the way this works or the way I use ExifTool or is it a problem with the reader of the metadata?

Thank you very much for any pointer!

all best
Pietro

[StarGeek]

This is basically FAQ #3.

Find a jp2 file which already displays the data in the other programs that you use.  Then run the command in FAQ #3 to figure out the locations you need to write.

But it is possible that the other programs simply don't read the metadata in the jp2 file.  As an example, even though PNG files can have a wide variety of metadata, Windows doesn't read any of it except the PNG:CreationTime.  Overall, metadata support for PNG files in any program is slim to none.  This might also apply to jp2, as I don't believe that support for metadata in very common.

A quick check shows me that Windows has zero support for metadata in jp2 files.

[pietro]

Thanks a lot!

The pointer to FAQ #3 is really the key!

I now have a lot to learn, but will definitely find the way starting from there.

Kakadu, the processor I am using for the jp2 images supports metadata https://cantaloupe-project.github.io/manual/5.0/processors.html#Supported%20Features so, I am trying with

-use MWG -Creator='Surname, name' -Copyright='My comment'

If I understand FAQ #3 and this page on MWG https://exiftool.org/TagNames/MWG.html, a series of variants of the metadata will be written and in that way I have the maximum of possibilities that software will have something to read.

The derivate jpg or png generated from the cantaloupe image server will have to deliver some of these metadata, and I have guidance here to do so https://cantaloupe-project.github.io/manual/5.0/metadata.html .

Thanks, I really learned a lot with your response, without it I would have never been able to put things together!

[StarGeek]

If you really want to check nearly everything, you can download my MetadataTestFile.args and run the command listed there.  That will embed over 1,400 tag, most set as the name of the tag.  Date tags need to be looked up in the args file.  You can then look at the file with your other programs to figure out what tags are read.