The File Batch Renamer lets you grab several files of any type.
Choose a common name and numbering style, select your output folder,
and let the Renamer do all the work.
Checks on filesize (optional also on the SHA1) of files.
It give out a sorted list. In this list files to delete can selected and also files can opened with an doubleclick (easier to verify if a file is an dupicate or not)