The online measurement of optical distortion for glass defect based on the grating projection method

Abstract In order to measure the optical distortion of float glass defect and obtain more accurate online measurement result, a novel online measuring method based on digital raster projection is proposed in the present paper. In this novel method, the deformation degree of optical distortion is represented as the diopter; thus a mathematical model is derived to describe the relationship between diopter and phase of fringe image. The image processing algorithm based on one-dimensional Fourier transform and elimination method of edge effect based on spliced removal method are used to process the fringe image. Finally, a diopter distribution of fringe image is obtained. The result shows that this novel method is able to fulfill the online measurement of the optical distortion with a higher accuracy of diopter which is up to 0.04 D.