ExifTool Forum

ExifTool => The "exiftool" Application => Topic started by: LaurentG on March 11, 2025, 05:17:04 AM

Title: How to remove Samsung makernotes data, without removing all metadata
Post by: LaurentG on March 11, 2025, 05:17:04 AM
Hi,

I have a photo that contains VERY large metadata from Samsung
[MakerNotes:Samsung] DepthMapWidth              : 1024
[MakerNotes:Samsung] DepthMapHeight             : 576
[MakerNotes:Samsung] EmbeddedImageName          : DualShot_1
[MakerNotes:Samsung] EmbeddedImage              : (Binary data 3434120 bytes, use -b option to extract)
[MakerNotes:Samsung] DepthMapName               : DualShot_DepthMap_1
[MakerNotes:Samsung] DepthMapData               : (Binary data 589824 bytes, use -b option to extract)
[MakerNotes:Samsung] TimeStamp                  : 2024:11:19 15:11:57.373+01:00
[MakerNotes:Samsung] MCCData                    : Italy (222)

More than 4 Mb for EmbeddedImage + DepthMapData !
After removing all metadata, the image itself is "only" 2.8 Mb !....

I don't know how (and where) these data came, it's the ONLY photo taken with my samsung S23 that includes such data....
And clearly, they are (at least for me) 100% useless !

I tried to remove them with exiftool image.jpg -makernotes=, or -makernotes:all=  but it does not remove anything
I tried also with -samsung:all=   but the answer is "not a deletable group, nothing to do"
I tried also to remove "only" large tags, -EmbeddedImage=  , but the answer is "Sorry, embeddedimage is not writable. Nothing to do".

The only way I've found is to remove all metadata : exiftool image.jpg -all=
But I do not want to remove all ! I'd like to keep all of them, except the one, useless, that are very large. Ideally, I would like to remove not all the samsung group, but keep Timestamp and MCCData and remove the others....

How can I do that ?
Title: Re: How to remove Samsung makernotes data, without removing all metadata
Post by: ywzc on March 11, 2025, 06:59:56 AM
I suspect that the solution would be to delete the trailer Trailer:All=. Many embedded thumbnails referenced in MakerNotes are stored in the trailer of the image.

Also, check out the Samsung Tags (https://www.exiftool.org/TagNames/Samsung.html) page for more details, maybe you will find something useful.
Title: Re: How to remove Samsung makernotes data, without removing all metadata
Post by: LaurentG on March 11, 2025, 07:26:22 AM
Thank you, it worked "almost" fine.
Why "almost" : because with -trailer:all=  it actually deletes all the samsung group, ie. deletes also MCCData and TimeStamp I'd like to keep, but it's a minor drawback vs do nothing.

I apply in a first time... and I hope that Phil a/o StarGeek may have an "even better" solution ?
Title: Re: How to remove Samsung makernotes data, without removing all metadata
Post by: LaurentG on March 11, 2025, 09:45:05 AM
I have had a look to this "EmbeddedImage" with more than 3 Mb....

Actually, it's a JPG image of the same resolution than the "main" image, that has its own Exif and other metadata.
But on the other hand, do not include "level 2 embedded" images in it (not even Exif thumbnail). It's not a russian doll ;)
Actually, the only missing data are the Exif Thumbnail (and other data from [IFD1] group, resolution, compression, width and height), the FlashpixVersion tag, and the Samsung MakerNotes.
According to some of these timestamp data, it has been taken 1/1000 second after the "main" image.

The best, in this story, is that this "embedded" image is even slightly better than the "main" image. Eventually, I kept this one rather than the original "main" image.
I still don't know what I did to have this behavior when taking this photo. It never occurred before (I have my S23 almost 1 year ago), and never since this one....
And I do not really understand the purpose of such a behavior....
Title: Re: How to remove Samsung makernotes data, without removing all metadata
Post by: StarGeek on March 11, 2025, 11:03:21 AM
Quote from: LaurentG on March 11, 2025, 07:26:22 AMI apply in a first time... and I hope that Phil a/o StarGeek may have an "even better" solution ?

From a previous post by Phil, emphisis mine
Quote from: Phil Harvey on May 23, 2019, 09:18:58 AMSorry, but the TimeStamp is stored in the Samsung trailer, which is not currently writable.

If you check the the trailer section under Supported JPEG Meta Information (https://exiftool.org/index.html#Trailers), you will see that the Samsung trailer is still not writable.