4K (computer virus)
4k is a computer virus which infects COM files and EXE files. The virus was one of the first to employ stealth tactics. Infected systems will hang, after September 22 every year, which is also the date of birth Bilbo Baggins, a character from "The Lord of the Rings". The code was intended to display the message "Frodo Lives", but hangs in all known variants.
4K resolution
Pixel shifting, as described here, was pioneered in the consumer space by JVC, and later in the commercial space by Epson. That said, it isn't the same thing as "true" 4K. More recently, some DLP projectors claim 4K UHD (which the JVCs and Epsons do not claim).