Open ITC File
The ITC file stores album covers and song metadata that have their respective covers associated with them.
The ITC extension stands for iTunes Cover, and it is used by iTunes to speed up browsing of songs in Cover Flow mode.
By using ITC files, the album art for each song should not be downloaded every time the track is played or during track browsing, as the file stores related metadata.
iTunes is a multimedia service, developed by Apple Inc. which, among other things, is used to purchase, play, download and organize digital multimedia on personal computers running the macOS and Windows operating systems.
iTunes has options for sound optimizations, as well as ways to wirelessly share your iTunes library.
Software to open an ITC file
ITC files are referenced by iTunes but are not intended to be opened manually.
You can download album artwork from your iTunes library by selecting "Get Album Artwork" from the Advanced menu in iTunes.