Semispatial, robust, and accurate phase evaluation algorithm

A new semispatial, robust, and accurate phase evaluation algorithm for spatial carrier fringe measuring systems is presented, which is a combination of a temporal algorithm and a spatial algorithm in order to use the advantages of both methods. Only two to four frames are needed for operation. A new interlaced detection mode is also presented. Thus the time of data acquisition can be reduced further. Limits are discussed and compared with conventional algorithms. An application of this algorithm with a fringe projection system is described and demonstrated by the measurement of objects with different optical properties. Using this algorithm it is possible to achieve short data-acquisition times of 80 ms in combination with a high vertical resolution. This fact is demonstrated by the measurement of living corneas.