Delete old metadata

[SteveF48]

Many of my old files have data in the Subject field. e.g. From Photoshop Elements, Microsoft Gallery, Picasa...
I tried:-
exiftool -Subject:All= P1020868.*
Exiftool replied:-
Warning: Not a deletable group: Subject
Nothing to do.

The Tag Subject is in the list of data generated by Exiftool, see attached, please tell me what I'm doing wrong.
Thanks in advance
Steve

[Alan Clifford]

Many of my old files have data in the Subject field. e.g. From Photoshop Elements, Microsoft Gallery, Picasa...
I tried:-
exiftool -Subject:All= P1020868.*
please tell me what I'm doing wrong.
Thanks in advance
Steve

exiftool -Subject= P1020868.*

[SteveF48]

Thanks, how do I repeat this for Supplemental Categories?
I've tried exiftool -"Supplemental Categories"= which gives Invalid Tag Name & Error File not Found 'Categories'
and exiftool -'Supplemental Categories' only says Invalid Tag Name.

Thanks in advance,
Steve

[SteveF48]

It seems to work if I just omit the space so SupplementalCategories instead of Supplemental Categories, but...
I ran it on 5 years worth of files successfully, but more recent years failed "No Matching Files". There are files in subfolders under 2004, 2005 etc. and at least 1 of the files contains data in Supplemental Categories.
Not sure what is going on.

[StarGeek]

Read FAQ #2 and FAQ #3.

If you're not including the -s (-short) option, you're listing the tag descriptions, not the tag names (FAQ #2).  Use the command in FAQ #3 to get names and locations, as well as listing tags with duplicate names. 

In most cases you would use the name in the second column to delete the tag (see below).  If you need to delete a tag that has duplicate names in other groups, i.e. delete IPTC:Headline while leaving XMP:Headline untouched, you would add the group name to the left of the colon.

Example:

Code Select Expand

C:\>exiftool -G1 -a -s -e y:\!temp\Test4.jpg
[ExifTool]      ExifToolVersion                 : 12.30
[System]        FileName                        : Test4.jpg
[System]        Directory                       : y:/!temp
[System]        FileSize                        : 435 KiB
[System]        FileModifyDate                  : 2020:08:21 12:00:00-07:00
[System]        FileAccessDate                  : 2021:08:24 07:51:50-07:00
[System]        FileCreateDate                  : 2021:08:08 02:24:06-07:00
[System]        FilePermissions                 : -rw-rw-rw-
[File]          FileType                        : JPEG
[File]          FileTypeExtension               : jpg
[File]          MIMEType                        : image/jpeg
[File]          CurrentIPTCDigest               : 24da67a399b2e0e72152ed3434406e18
[File]          ImageWidth                      : 1749
[File]          ImageHeight                     : 1205
[File]          EncodingProcess                 : Baseline DCT, Huffman coding
[File]          BitsPerSample                   : 8
[File]          ColorComponents                 : 3
[File]          YCbCrSubSampling                : YCbCr4:2:0 (2 2)
[IPTC]          SupplementalCategories          : Test
[IPTC]          ApplicationRecordVersion        : 4

C:\>exiftool -P -overwrite_original -SupplementalCategories= y:\!temp\Test4.jpg
    1 image files updated

C:\>exiftool -G1 -a -s -e y:\!temp\Test4.jpg
[ExifTool]      ExifToolVersion                 : 12.30
[System]        FileName                        : Test4.jpg
[System]        Directory                       : y:/!temp
[System]        FileSize                        : 435 KiB
[System]        FileModifyDate                  : 2020:08:21 12:00:00-07:00
[System]        FileAccessDate                  : 2021:08:24 07:52:10-07:00
[System]        FileCreateDate                  : 2021:08:08 02:24:06-07:00
[System]        FilePermissions                 : -rw-rw-rw-
[File]          FileType                        : JPEG
[File]          FileTypeExtension               : jpg
[File]          MIMEType                        : image/jpeg
[File]          ImageWidth                      : 1749
[File]          ImageHeight                     : 1205
[File]          EncodingProcess                 : Baseline DCT, Huffman coding
[File]          BitsPerSample                   : 8
[File]          ColorComponents                 : 3
[File]          YCbCrSubSampling                : YCbCr4:2:0 (2 2)

[Alan Clifford]

I ran it on 5 years worth of files successfully, but more recent years failed "No Matching Files". There are files in subfolders under 2004, 2005 etc. and at least 1 of the files contains data in Supplemental Categories.
Not sure what is going on.

Did you specify -recurse in your command?

[SteveF48]

I rearranged the command and put the folder at the end and that at leaset processed the files.
This time I received a lot of warnings referring to darktable fields. e.g. Warning: [minor] Ignored empty rdf:Seq list for darktable:masks_history - D:/Photos/2005/2005-08-August/G-REEN Cessna 340-a.JPG.xmp

The list suggested by StarGeek shows the following:-
[XMP-darktable] Import_timestamp                : 1629550480
[XMP-darktable] Change_timestamp                : -1
[XMP-darktable] Export_timestamp                : -1
[XMP-darktable] Print_timestamp                 : -1
[XMP-darktable] Xmp_version                     : 4
[XMP-darktable] Raw_params                      : 0
[XMP-darktable] Auto_presets_applied            : 0
[XMP-darktable] History_end                     : 0
[XMP-darktable] Iop_order_version               : 2
[XMP-darktable] Masks_history                   :
[XMP-darktable] History                         :
How do I delete all of these fields without specifying them individually?

Thanks in advance,
Steve

[StarGeek]

Warning: [minor] Ignored empty rdf:Seq list for darktable:masks_history - D:/Photos/2005/2005-08-August/G-REEN Cessna 340-a.JPG.xmp

It's a minor error and can be ignored.  It just means that Darktable is created entries that have no data in them.

How do I delete all of these fields without specifying them individually?

You could use this and all XMP-darktable tags will be deleted
exiftool -XMP-darktable:All= /path/to/files/

[SteveF48]

I'm obviously still not getting it, because this command only processes the specified folder.
exiftool -xmp-acdsee:all= -xmp-microsoft:all= -xmp-darktable:all= \Photos\*.xmp -r -overwrite_original

Does -r(ecurse) have to appear in a specific position in the parameters?

[Phil Harvey]

You must specify a directory name on the command line for the -r option to be meaningful.  You have specified \Photos\*.xmp, but you can't recurse into an xmp file.  Use \Photos -ext xmp instead.

- Phil

[StarGeek]

Doc links, see Common Mistake #2 and the -r (-recurse) option.

[SteveF48]

Thank you both for your assistance.
Steve