Notes about the PRP file extension:
To open this file type, a required software must be installed. Without it you only see a Windows message "The following file cannot be opened
" (Windows 7) or "How do you want to open this file?
" (Windows 10) if you double-click the file. There click on "More apps"
and choose a suitable software to view such files on your PC or from email attachments.
The PRP file type is primarily associated with 'Compressed GIMP Image with Properties of GIMP'. XJT uses JPEG compression for each layer or channel and TAR to collect all layers in one file. (Layers with alphachannels are split into 2 JPEG files). Additional property information about offsets, opacity, layer names etc. are stored in the readable textfile called "PRP" (Properties). The resulting tar-file is optionally compressed a 2nd time using GZIP or BZIP2 (filename ends in "gz" or "bz2" accordingly).