This is a format for editing, storing, and transmitting images with metadata for scientific purposes. The main application is astronomy. The main emphasis is on the metadata, which contain information about spatial and photometric calibrations. FTS is often used for storing data without including the actual associated images. It supports the storage of databases, matrices, etc.
ICO is a file of this format usually contains a small image icons of different resolutions (16x16, 32x32, 64x64 pixels) and various color depths (16 colors, 32, 64, 128, 256, 16-bit, and so on). Used to display files and folders in the graphical user interface (GUI) operating systems. This format can be opened with the help of the program ACDSee.