XV thumbnail
From Just Solve the File Format Problem
XV thumbnail is an image file format used by the XV image viewer for its thumbnail cache. The color format is 8 bits/pixel RGB 3-3-2.
Identification
Files begin with ASCII text "P7 332", followed by a newline.
Note that they could easily be mis-identified as PAM format.
Specifications
The format is described in a "THUMBNAIL FILE FORMAT" comment in the xvbrowse.c file from the XV source distribution (v3.10a, at least).
