I see your post about no replies 
As Ofnuts posted Does anyone really have an answer ? No answers therefore no replies.
I don't play these game programs so BLP files are a mystery to me. However a search did come up with a gimp blp plugin, but only one that loads it does not save. Even worse for you is it is the code for compiling the plugin. I use linux so while I can (after a bit of a struggle) get it working. Up to you to compile it for Windows and then I had another struggle to find some sample blp files.
this is the code: https://web.archive.org/web/201703272346...porter.41/ It says script-fu - do not be fooled, it is code.
A better bet for you is a Windows command line utility that converts between blp and png and back again.
see: https://www.wowinterface.com/downloads/i...erter.html
As Ofnuts posted Does anyone really have an answer ? No answers therefore no replies.
I don't play these game programs so BLP files are a mystery to me. However a search did come up with a gimp blp plugin, but only one that loads it does not save. Even worse for you is it is the code for compiling the plugin. I use linux so while I can (after a bit of a struggle) get it working. Up to you to compile it for Windows and then I had another struggle to find some sample blp files.
this is the code: https://web.archive.org/web/201703272346...porter.41/ It says script-fu - do not be fooled, it is code.
A better bet for you is a Windows command line utility that converts between blp and png and back again.
see: https://www.wowinterface.com/downloads/i...erter.html