Peak detection from saturated signals
Depends on the amount of clipping and what other information about the signal you have. It's pretty easy to detect clipping (wave form constant at +xmax or -xmax). Once a region has been found you can try to replace the clipped region with an interpolation from the non-clipped regions around this. The best interpolation scheme will depend on what else you know about the signal. You can try polynomial expansions, Taylor series, Frequency domain interpolation, etc.