ddp

ddp level coef sigma

ddp performs a DDP (digital development processing) as described first by Kunihiko Okano. This implementation is the one described in IRIS:
http://www.astrosurf.org/buil/us/iris/iris5.htm
It combines a linear distribution on low levels (below level) and a non-linear on high levels. It uses a gaussian filter of sigma sigma and multiplies the resulting image by coef.