Phase-unwrapping algorithms, an active and interesting subject in recent years, are important in a great number of measurement applications. Active research is being undertaken to develop reliable and high-speed procedures. The current process uses a gray-scale mask and the flood-fill concept from image processing for phase unwrapping. The algorithm unwraps phase from an area with higher reliability to one with lower reliability. In addition to robustness, the speed of the algorithm proposed is much faster than conventional routines. The experimental results of different algorithms are compared by analysis of a tooth plaster and a photoelastic specimen.