A small program that I made to clean up my wallpapers folder, it moves all images that are not a specific aspect ratio to another folder.
Simply run the program in a directory full of images and it will move all images that are not 16:9 aspect ratio to a folder called notwallpapers one directory up.
Alternatively you can pass arguments to specify the input folder, output folder, if you would like it to recursively search directories and aspect ratio.
NotWallpapers.exe C:\wallpapers C:\notwallpapers false 0.5625