config file tag definition for IPTC KeyWords style tag

[calberga]

I have attempted to create a new IPTC tag which behaves like the KeyWords tag.  I copied the "Format" value from that shown for KeyWords, i.e.

198 => {
           Name => 'People',
           Format => 'string[0,64]+',
        },

(This is buried in a list of other custom tags.)

but this gives a syntax error.

What should the Format be defined as?

[Phil Harvey]

Just drop the "+" sign and all should be good.

- Phil

[calberga]

Thanks, I had blindly copied from the "writable" column in the IPTC tag list, assuming that the + was needed to allow adding multiple items to the value.  I searched for the syntax of the "Format" line in the definitions, but couldn't find it.  Is this documented someplace?

[Phil Harvey]

The best documentation for this are the examples of tag definitions in the ExifTool source code (for example, here on sourceforge).  The actual documentation is in lib/Image/ExifTool/README, but it isn't detailed enough to cover all the nuances of the Formats for all metadata types.

- Phil

[calberga]

Unfortunately, I can't seem to make it work.  I'm trying to move all the "face" information (in my own crazy format) from the KeyWords tag to the custom defined tag People, so I can use KeyWords for other things and not have to sort through them to find the "faces".  I hoped that I could just run a recursive application of -People=$KeyWords.  That didn't work, so I tried adding -sep ", " since that seemed to be what the value of -Keywords was.  That still didn't work. 

I've been setting the KeyWords using and args file containing lines such as:

Code Select Expand


-Keywords=("Alberga, Emma C." 0 13926 43212 65535)
D:/P/Working/00060637.jpg
-execute
D:/P/Working/00060637.jpg
-execute
-Keywords=("Alberga, Emma C." 54185 12237 61944 19609):("Alberga, Katherine Ansell" 40975 10445 46939 16077)
D:/P/Working/00060638.jpg
-execute
D:/P/Working/00060638.jpg
-execute
-Keywords=("Alberga, Emma C." 15973 40396 22467 45772):("Alberga, Katherine Ansell" 46352 35327 53891 41523):("Morikado, Logan" 8136 39833 15301 45721)
D:/P/Working/00060639.jpg
-execute


invoked by:

Code Select Expand

exiftool -@ "D:/P/X/D-r-kw-updates.args" -common_args -L -V0 -P -overwrite_original -sep ":"

which works just fine. 

But I haven't figured out anything that will copy the data into the new tag.  Any variation that I've tried on:

Code Select Expand

exiftool  -ext jpg -charset cp1252 "-People<$KeyWords" -overwrite_original -sep ", " -F -r -P -v0 "D:/Working/"

results in data truncated to 64 bytes.  So is there a way to define a customn tag that acts the way KeyWords does?

[Phil Harvey]

So is there a way to define a customn tag that acts the way KeyWords does?

Yes.  Just do exactly like the Keywords definition in the source code (see the link I posted).  Did you make it a "List"-type tag?

- Phil

[calberga]

I apologize for hesitating to look at the source code.  I was daunted by the idea of having to wade through a language the syntax of which I was unfamiliar.  But with your prodding I see that it is quite clear.  Thank you for your patience.