FreeFrame 1.0 is no longer supported so there's no cpu processing for images anymore. You need to use OpenGL to render textures. You can start by looking at the AddSubtract effect for example. When you're following an OpenGL tutorial pay particular attention to framebufferobjects, that's what you need to capture opengl output if you're interrested in that.
Nice tutorial! All the way from explaining and coding for a BMP file to using DXT compressed textures. Interested to run through that myself some time.