I01 file format is used by DVD Shrink software tool, a program for creating DVD-Video backup copies. A single copy is typically composed of several disc image files, each with subsequently numbered extension, i.e. I00, I01, I02, etc. I01 file is the second of the disc image files that comprise the full copy.

Disc image copy need not necessary contain all the original source’s data. DVD Shrink tool allows users to exclude certain data, such as audio track or subtitles, and offers a data compression feature.