OpenGL speedUp vs CUDA SpeedUp

Dear All

There are reports of very large OpenGL speedUp of Graphics algorithms using Shaders, Textures

1st Can processing with CUDA achieve the same speedUPs? I think it is used buildin OpenGL functions (that are perhaps very optimized and with low level programming). There are, or not, buildin CUDA optimized functions that do the same operations of OpenGL or call OpenGL driver functions from CUDA?

2nd If so. After done the processing can be transferred a pointer to OpenGL for displaying the final image?

Thanks

Luis Gonçalves