> I want to synchronize the keywords that I assign into Thumbplus to the exif file in order to make it available for other user who has not Thumplus or to view in other software (like geosetter that enable geographic query)
You'd use Image | Batch Edit Metadata for that (but first select the images that you want to process with it).
For "Field", you pick Keywords in the Description section. This corresponds to the IPTC keywords field in the image file.
Then choose the desired operation (e.g. set or append).
For "From" you select Image Info | Keywords (these are the keywords that you saved in the database).
Then press Add to add this command to your batch command, and press OK to apply it to the selected images. This will copy the database keywords of each image into its EXIF/IPTC file header. You can save the batch command for future use.
