BLP2PNG 

IMPORTANT

BLP2PNG is obsolete. The sources have aged and the project no longer builds correctly. There is another tool which is nice and works very well named BLPNG and it's also here on WoW Interface. I recommend it and I've been using it for my addon development lately instead of my own tool.

If you're still wanting to play with BLP2PNG, here's the old description/instructions:

BLP2PNG does not have a graphical user interface. You can drag-and-drop files or folders onto it and it will convert them, or you can use it from command-line environments such as development tools (as I do). If you're looking for a tool with a file picker and buttons, this isn't it.

Description

This tool is used for converting bi-directionally between BLP and PNG images. The tool fully supports alpha channels and can be used as a drag-and-drop converter or from the command line. It can also convert your existing TGA files to PNG.

BLP2PNG will convert the file based on the original type:

* BLP are converted to PNG
* BMP are converted to PNG
* TGA are converted to PNG
* PNG are converted to BLP

If you drop a folder onto it, it will recursively convert every BLP image in the folder to a PNG. This is very handy for mass-converting the Blizzard artwork folder after a new patch.