Moiré interferometry is a common tool if depth estimation from a single image frame is desired. It uses the interference of periodic patterns to measure the topology of a given surface. The actual depth estimation relies on the consistent phase estimation from the interferogram. We show that this task can be simplified by estimating the image phase and the local image orientation simultaneously, followed by a processing step called orientation unwrapping which is introduced in this paper. We compare two methods for extracting image phase and orientation and present experimental results.