HTC splashscreen

A HTC splashscreen is an image used on HTC Android-based phones on startup. It is in a raster graphic format known as "NB" (apparently unrelated to the Mathematica notebook format). While a BMP-to-NB converter program exists which saves the image files in a .nb extension, the HTC actually uses them with a .img extension, contained within a ZIP file along with a  file giving some metadata.

android-info.txt contents
This is a sample android-info-txt (downloadable here):

hbootpreupdate:13 modelid: PH3910000 cidnum: CWS__001 mainver: 3.26.502.56 hbootpreupdate:12 DelCache:1

Links

 * How to change your HTC splash screen
 * nbimg conversion utility