Extracting image assets from game client

Steps

1. Download GCFScape (msi or zip) from here.
2. Using GCFScape, load the .vpk file from the game client you'd like to extract from. (Typically pak01_dir.vpk)
3. Download Dota 2 ModKit from here.
4. Image files within .vpk files are stored as .vtex_c files. Extract the ones you want using GCFScape to a directory of your choice.
5. In Dota 2 ModKit, select T2, and the click the button titled ".vtex_c -> .tga"
6. Follow the on screen prompts to get your .tga files.

To get transparency

By default, .tga files do not have transparency. To get PNGs with transparency, follow these steps.

1. Using Adobe Photoshop, open the .tga file.
2. In Channels, Ctrl + Left click the Alpha Channel to copy it.
3. In Layers, click the Create New Mast button.
4. Save the resulting image as a .png file.