Error analysis of a zero-crossing algorithm for fringe location

A theoretical analysis of the fringe location error of a sampled intensity distribution when using a zero-crossing algorithm is performed. The theory assumes a sinusoidal distribution with local constant phase modulation. The error function is analyzed with respect to the number of pixels per fringe period α, the location of the fringe maximum within a pixel, and the error in computing the mean intensity. It is shown that for reasonable values of α, the fringe location error will be less than the error caused by jitter in the line sync signal if the error in the mean intensity is kept below certain limits.