Complementary metal-oxide-semiconductor (CMOS) transistor cameras instead of conventional photoelectric detectors are used to obtain planar information and can improve the tolerance of electromagnetic interference and measurement precision. Three algorithms are proposed to extract central finges. With a proper design of low-coherence Young′s fiber interferometer, these algorithms are tested experimentally. The result shows that covered area comparison algorithm is most efficient and the central fringe is marked accurately. In addition, it is suitable to real-time information display systems.