| Moire deflection technology (MDT) is a non-contact optical measuring method. Principle of Moire Deflection Technology (MDT) is the combination of moire effect and Talbot effect.Moire deflection technology (MDT) had been researched for nearly three decades, the measurement precision of this technology has been further improved with the development of optical3D measurement technology. At the same time, the complex refraction distribution lens appeared with the development of Optometry Technology. The traditional single-point lens measurement method can not be used to measure the whole diopter of the lens. For some related studies of MDT, a new measurement method was proposed and a measurement system had been set up.In this dissertation, the study of Moire image processing and lens diopter measurement were carried out based on a measurement system with MDT. The main contents are as follows:1. The-theories and principles about MDT were introduced in detail. The process of the Lens diopter measurement by MDT has been simulated. And a novel Lens diopter measurement system was designed. The optical path of measurement system and some devices were discussed.2. The Moire fringe image processing was studied in depth, which included median filtering, thresholding, thinning, curve (straight line) fitting, numerical calculation surface reconstruction, and so on.3. A lens diopter measurement software which based on MDT were designed with Lab VIEW8.6. The measurement software consists of three modules:image acquisition module, image processing module, output module which could accurately measurement of different lens diopter value.4. The Lens diopter measurement system which based on MDT was accomplished. The results of measurement were discussed. First, the relative error and repeatability error were calculated, and then the source of measurement error was analyzed. The measuring system meets the lens diopter measurement requirements and the measurement error is0.4%. |
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