You can get a months worth of playing with your images in DDS format by downloading the trial version of either of the software packages Taco mentioned. TGA is also a workable solution, but have not tried it myself.
You will need to limit your image to a dimension of a power of 2 (example 128,128 or 256,256).
The easiest method to start out is to grab an already formatted image that has the RBG channels and the Alpha channel. Once you get a handle on the commands it will be as easy as working in Corel.
Best of luck!
|