On Thu, 2017-09-07 at 11:04 +0100, steve-ALUG@hst.me.uk wrote:
The other solution. Use a tool to read the exif data of all files (is it exiftool?). Work out the image sizes. Work out what sizes your thumbnails are. write a script to delete or move these files somewhere else where they can be manually pruned.
Won't full size images and their thumbnails have close (identical?) creation dates in the EXIF data? You could use that to identify matching images.
Other than doing some kind of Google-esque image recognition, I don't think there's any way of matching them by appearance!