PHASE-SHIFTING PHASE MEASUREMENT ERROR CORRECTION METHOD BASED ON PIXEL TRACING OF OBJECT RASTER IMAGES

摘要

Disclosed is a phase-shifting phase measurement error correction method based on pixel tracing of object raster images. During traditional phase-shifting shape measurement, surface height information is represented by phase information. The nonlinearity of equipment inevitably causes errors of phase information calculated according to images captured by a camera. The method comprises: projecting, by projector, a special raster projection to resolve a pixel-tracing mapping relation; in a direction against a light path, determining the position of a point light source that illuminates any one image pixel in a captured image and is located in an imaging plane of the projector according to the pixel-tracing mapping relation; and finally, replacing distributed phase information in image pixels with ideal phases in point light sources to correct phase errors to improve the accuracy of phase-shifting shape measurement. Compared with existing methods, the method is easy to operate and high in efficiency and precision.