Hi Phil,
Using the same file, I added information to a number of tags via PhotoShop CS2, and saved it as 5253a.psd. Next I issued the following commands:
-a -u -g1 5253a.psd >> 5253.txt
echo. >> 5253.txt
echo. >> 5253.txt
-a -u -g1 5253.psd >> 5253.txt
This gave me a file that listed all of the Tags in 5253a.psd, two blank lines, and all the tags in 5253.psd.
The first question is: "Artist" shows up in 5253a.psd, under the IDFO heading; but not in 5253.psd. Yet when I search for -IDFO:Artist, it does not show in either file; while a search for -Artist does. Is the Artist tag not in the IDFO group?
Another question, and I guess I'm just not understanding the, I'll call it "existence" of Tags, a search for the Artist tag, without the -f option, Artist does not print out unless it has been assigned a value. I understand that part. In a search with the -f option, the tag name is displayed, followed by a dash. I understand that, too. What I don't understand is: Does the Artist tag actually exist in the file, but simply has no data in it? Or is it created when I issue a command like -Artist=me?
Along with that, a search for -Artist and -TwoDogsAndABeer, without the -f option reveals nothing for either tag. Obviously, as Artist has nothing in it and TwoDogsAndABeer doesn't even exist. Yet, with the -f option, they both are displayed and have a dash folling them. At this point, I can write information to -Artist, but not -TwoDogsAndABeer. Why is that? Or maybe I should ask why does it seem that I can "create", so to speak, the Artist tag (which does not show up with the -a -u -g1 search) but I cannot create the TwoDogs tag?
Thanks in advance.
Quote from: Tarn on March 28, 2013, 04:40:51 AM
The first question is: "Artist" shows up in 5253a.psd, under the IDFO heading; but not in 5253.psd. Yet when I search for -IDFO:Artist, it does not show in either file; while a search for -Artist does. Is the Artist tag not in the IDFO group?
It should be in IFD0, but I have seen it written incorrectly into the ExifIFD by some software.
QuoteAnother question, and I guess I'm just not understanding the, I'll call it "existence" of Tags, a search for the Artist tag, without the -f option, Artist does not print out unless it has been assigned a value. I understand that part. In a search with the -f option, the tag name is displayed, followed by a dash. I understand that, too. What I don't understand is: Does the Artist tag actually exist in the file, but simply has no data in it? Or is it created when I issue a command like -Artist=me?
If the Artist tag exists but is empty, it will show up as an empty string (with or without
-f). If it shows up as a "-" with
-f then it doesn't exist (or contains the string "-", which is unlikely).
QuoteI can write information to -Artist, but not -TwoDogsAndABeer. Why is that?
You can only write tags that are known to ExifTool. See the EXIF tag name documentation (https://exiftool.org/TagNames/EXIF.html) for a list of EXIF tags. The reason is that ExifTool must know the Tag ID, format and location to write a tag before it can be created.
- Phil
Hi Phil,
QuoteYou can only write tags that are known to ExifTool. See the EXIF tag name documentation for a list of EXIF tags. The reason is that ExifTool must know the Tag ID, format and location to write a tag before it can be created.
The light just came on! Okay! I got it.
Thanks