Unable to delete "Maker note" tag

[echt14]

In trying to streamline the EXIF info shown by ACDSee 3.1, I've gotten ExifTool to delete everything I wanted from jpeg files except for something shown as "Maker note."   See screen cap here: http://www2.pic-upload.de/img/31120150/acdseeexif.jpg

This tag/value doesn't show up in ExifTool when I drop the file on it, but it's apparently in there somewhere.  I've tried "-MakerNote=" but it doesn't get rid of it.

A sample image that generates the exif tag is here: http://www2.pic-upload.de/img/31120145/DSC_0428test.jpg

[StarGeek]

Try
exiftool -makernotes:all= File

Though take note, you do not want to do this with RAW files (.Nef, .Cr2) as the image may become unprocessable.

MakerNotes are proprietary info that a lot of camera makers include that have the various camera settings from when the picture was taken.

[echt14]

That did eliminate the "maker note" tag, but it unfortunately also removed about 60% of all the metadata! including a good many tags that I'd like to remain embedded.  I'm really only wanting to remove the one tag.

[Hayo Baan]

I think acdsee is just showing you the binary format of the makernotes instead of interpreting its content. You can delete this (as you did), but as you noticed a lot of info is stored within the makernotes, info you want to maintain. So I think you have no alternative than to ignore acdsee in this case...

[echt14]

Are you saying it's displaying 50+ tags as one tag?  If so, that's odd behavior, but as I mentioned, I wasn't able to find this tag when I dropped the file on Exiftool.    I guess it's not a big deal, but it seems like it should be theoretically possible to delete anything that shows up as an individual tag.  Looking through the tag lists on this site I was able to find another one, "-MakerNoteNikon=" but it also removed all the data.

[Phil Harvey]

The "MakerNotes" tag is a shortcut for all of the various makernotes from different manufacturers.  This may be accessed as a block to delete or copy the entire makernotes.  If ExifTool recognizes the makernotes when reading it will parse the block and extract any information it can decode from within.

- Phil

[echt14]

So is the block of tags known as maker notes some kind of compiled or encrypted entity that can't be accessed per individual tag?  If various software can unlock/decrypt and display them individually, why can't they be accessed individually for deletion?   Sorry for being dense about this, but I'm not familiar with the way this data is embedded, and I'm not grasping why an item (tag) that can be written and displayed individually can't be isolated for deletion in a jpeg file.

[Phil Harvey]

The format of the makernotes is not specified, so removing a single tag may make the makernotes invalid.  That is assuming that they are stored as tags in the first place.  If it is a simple binary data block with no supporting structure, then certainly removing a chunk from the middle will invalidate the rest of the block.

And yes, sometimes it is encrypted, but ExifTool can handle the encryption/decryption so that isn't the reason that ExifTool doesn't let you delete an individual tag.

From the exiftool application documentation for the -TAG[+-]=[VALUE] argument:

            2) In general, MakerNotes tags are considered "Permanent", and may
            be edited but not created or deleted individually.  This avoids
            many potential problems, including the inevitable compatibility
            problems with OEM software which may be very inflexible about the
            information it expects to find in the maker notes.

- Phil

[echt14]

It sounds like "invalidate the rest of the block" means it would prevent the rest of the maker data from being displayed.  That's disappointing, but makes more sense now.  I do wish it were designed with more modularity, but oh well.  Thanks for all the info.

[Hayo Baan]

It is not the makernotes that are your problem here at all (even though they should have been implemented better by camera manufacturers), it is acdsee's inability to interpret them, but still showing the tag as binary block. I suggest you ask the developer of acdsee to inhibit showing the Makernotes tag.

[StarGeek]

According to this page (near the bottom), there should be a setting to turn off the display of MakerNotes, though that might turn off the display of info from the MakerNotes that you want to see.

[echt14]

Unfortunately this version of ACDSee, 3.1 is old and as far as I've been able to find, does not allow for any customization of EXIF items.  I've tried many different and newer image viewers, but return to ACDSee 3.1 because of its streamlined basic functionality, pane/bar customizibility, keyboard shortcuts for display order, and lack of bloat.  I guess I'll just have to live with the long maker note tag at the bottom.