An image file contains the korean ‘special case’ functions are already in use. Look at the link below. korean filename is stored in a state where untested apply ‘html_entity_decode’.
Also it looks even need treatment for bmp files.
When you update the media library, but the image is actually a duplicate file was confirmed to be one. So it would not unnecessarily increase disk capacity. When you update a list of files in the Media Library when I think that even with cleanup.