  Phase imaging techniques extract the optical path-length information of a
scene, whereas wavefront sensors provide the shape of an optical wavefront.
Since these two applications have different technical requirements, they have
developed their own specific technology. Here we show how to perform phase
imaging combining wavefront sampling using a reconfigurable spatial light
modulator with a beam position detector. The result is a time-multiplexed
detection scheme, capable of being shortened considerably by compressive
sensing. This robust reference-less method does not require the phase
unwrapping algorithms demanded by conventional interferometry, and its
lenslet-free nature removes tradeoffs usually found in Shack-Hartmann sensors.
