There is only one file type that uses the .VDA extension:
Targa Bitmap Image File
Raster image formatted in the Targa Truevision format; stores image data using 1 to 32 bits per pixel, with 24 bits possible for the RGB data and 8 bits for the alpha (opacity)channel.
The TARGA format was originally developed by Truevision, which was later acquired by Pinnacle Systems. Most TARGA files use the .TGA extension.
Updated: September 18, 2009