imageiio.pe3, imaginfo.pe3, imageiio.pe4, and imaginfo.pe4 are the names of files that are auto-generated by some graphics applications from Ulead Systems. A pair of PE3 files, or of PE4 files, generally appears together. They presumably contain a thumbnail cache, and other indexing information.
Applications reported to create such files include iPhoto Plus, PhotoImpact, and Photo Explorer.
Some or all imageiio.pe3 files begin with ASCII "
Some or all imageiio.pe4 files begin with ASCII "
The imaginfo formats have no obvious signature. The version number such as three or four is stored in byte at offset 22.
- Ulead PhotoImpact 3.0 - CD image from archive.org (PE3 files)
- Ulead Systems iPhotoPlus 4 (ULEAD) (1996) - CD image from archive.org (PE4 files)
- Or try searching the web for the relevant filenames.