replace files

[jln]

I need to rescan and reprocess some files in my database with keywords, ratings, and locations already applied. Rescanning and reprocessing is straightforward.

How can I replace the old files with the new ones and retain the keywords, ratings, and locations?

[jch2103]

Just to clarify, when you say 'rescan', I assume you're talking about rescanning slides or negatives (e.g., for better quality). I've had occasion to do that a few times, but just did copy/paste of metadata from old to new images. I expect there may be a better way than that.

[Mario]

When you replace existing images, does your software retain existing metadata? Or does it just wipe it?
If you replace an image with metadata embedded by IMatch with an image without any metadata, IMatch cannot do anything for you.

I would make the new version of the image a version of the old image. This way you can automatically let IMatch propagate the metadata from the old version to the new version during a write-back.
Then you can delete the old version.

Or, if only a few images are affected, use the Copy / Paste Attributes command to copy what's needed. See Copying Attributes and Metadata Between Files

[jln]

I'm rescanning old color negatives. If I make the new files versions of the old ones, and I get rid of the old ones, is there a way to make these new version files master files?

[Mario]

Data transfers from the master to versions.
So your old versions must be masters in order to automatically propagate metadata.
After you have deleted the originals (after metadata write-back and propagating data to the versions) you can make the new files masters.

Keep it simple.
Store the new files in a new folder. This way you can easily differentiate between old files and new files in the file relations.
Propagate XMP data and let IMatch update the versions.
Keep in mind that the EXIF data in your old files and new files will probably very different, so better not propagate EXIF data.
Try with some sample files, and if you are comfortable and the results are OK. delete the no longer needed images.