Research on Image Process Based on GA in Conoscopic Holography Measurement

To resolve the difficulty in processing fringe image with heavy noise and low contrast in non-contact measurement based on conoscopic holography, B-splines function is calculated to approximate the phase from a single closed fringe pattern by conoscopic holography, which is fitted over the sub-image obtained from every space interval in a scanning window. Instead of fringe frequency used before, unwrap phase in the whole scanning window is acquired to improve the precision of measurement. The parameter optimization of fitness is achieved by multiple application of a genetic algorithm (GA). Experiment on an emulation fringe pattern without noise and with 20% noise separately, results show this method can offer high measuring accuracy with high noise immunity.