What to do with existing sidecar files? Change to embedded XMP

[Jim K.]

Using  IMatch first time in 2006 I decided to use xmp-sidecar files (for jpg), continuing with IMatch 5. After pausing for a while using IMatch, I started using IMatch 2023 last year. For the time getting  familiar again with the system, I tried to change as little to the previous settings (so kept with sidecar).

Now I would like to use embedded xmp only (as my understanding is it is not recommended anymore to use xmp sidecar for jpg files). So I changed settings testwise in "File Format Metadata Option" for jpg from "Force xmp sidecar file" to "Embedded xmp in file".

As far as I can see, it is all what one has to do (?). At least when I index new images and write back  there is no sidecar file created and all metadata are available (checking with XnView MP).

But what with the old jpg-files with sidecar files?

a.)   Does it make sense to get rid of the old sidecar file by somehow importing relevant data from sidecar to the image (embedded jpg) or better keeping as it is: until 2023 with sidecar, beginning with 2024 without?

b.)   If keeping sidecar for old images as described in a.), could it happen to loose metadata when change metadata in old images (with sidecar) with the new setting (no sidecar file)?

Thank's for your support.

[Mario]

Now I would like to use embedded xmp only (as my understanding is it is not recommended anymore to use xmp sidecar for jpg files).

JPEG files always uses embedded XMP. Like TIFF, PNG, PSD, PSB, PDF, DNG etc.

So I changed settings testwise in "File Format Metadata Option" for jpg from "Force xmp sidecar file" to "Embedded xmp in file".

You said you did not make changes to the default settings. But "Force XMP sidcecar file" is not a standard setting and not recommended.

The default setting for "XMP sidecar file" for the JPG/JPEG file forma is "Default". Which causes IMatch and ExifTool to embed XMP data into JPG files. I recommend to use this setting. Just re-enable "Use default setting" for JPG.

a) Using XMP for JPG file is not a good idea. You should undo this decision. The Command menu > File > Extras > Import XMP Metadata should be the first step. Make a backup copy of your files before. After checking the result (Metadata Panel, Metadata Analyst, ECP), delete the superfluous sidecar files to not hamper with metadata processing.

b) See a. Having XMP sidecar files and embedded XMP means calling for trouble. Two sources of truth for metadata is never good. Unless you have a RAW file with the same name as the XMP file in the same folder, delete them after importing.

c) Set the metadata options for JPG/JPG back to default.

The metadata options in IMatch are designed to work with established standards and industry practices. And to cooperate well with other applications used in imaging, videoing and other workflows.
Only in very particular and controlled situations users should make any change to metadata settings or per-format metadata settings. That's why these options exist. And why there are many warnings not to change them in the help system.

Users have been bitten by their decisions to use their 'own' rules over the years (like forcing IMatch to not synchronize embedded data in RAW files with XMP). I neither recommend nor support this.