Phase extraction from a single fringe pattern based on guidance of an extreme map.

A method for automatic phase extraction from a single fringe pattern based on the guidance of an extreme map is introduced. The method uses an adaptive weighted filter to reduce noise and enhance contrast and to locate the fringe extremes. Wrapped phase values are calculated by use of an arccosine function obtained from the extreme map. With this method, wrapped phase values can be efficiently demodulated from a single fringe pattern without the need for assigning fringe order or interpolating fractional fringe order. The validity of the method is demonstrated by use of closed-fringe patterns generated by digital speckle interferometry.