Research On The Modulation Processing Method Before Image Formation In Vision Measurement Application

Vision measurement as a major means of mechanical testing is widely used. With the development of advanced manufacture, vision measurement is required to be higher accuracy, higher efficiency, more smart and more flexible. Based on the catadioptric imaging structure, the thesis proposes the optical spatical modulation, the optical wavelength modulation and temporal pixel multiplexing before image formation. Subsequently, a self-adaptive high dynamic range imaging system is designed to remove the parasitic image due to glare effect. And a modulatable multispectral imaging system is designed for the application of color vision measurement. The main contents of the thesis is in the following:Multiple viewpoints imaging theory is summarized and concluded by deducing the characteristic of catadioptric imaging structure. The example that the large-scale ceramic is measured demonstrates the advantage of the proposed catadioptric imaging structure in vision measurement application. DMD-based multiple viewpoints imaging is characterized, and abide by the principle of Scheimpflug principle.The modulation processing researches before image formation contain optical spatial modulation, optical wavelength modulation and temporal pixel multiplexing. Based on the working principle description of optical spatial modulation, accurate CCD-to-DMD correspondence is adjusted by using the phase-shifting moiré method. Based on the working principle description of optical wavelength modulation, spetrum calibration method is presented.Self-adaptive high dynamic range imaging system is build and applied in vision measurement. Analyze the glare effect and the source of parasitic image. an effective method for removing the parasitic image is proposed. Specifically, a two-arm system for programmable imaging is first described. The strength of the optical system is to process scene ray before image formation. Based on the two-arm system, an iterative algorithm of modulated region selection, precise region mapping, and multimodulation provides removal of the parasitic image and reconstruction of a correction image.Modulatable multispectral imaging system is build and used in the application of vision measurement. Based on the color principles and properties, the modulatable multispectral imaging system is used to measure the spectral reflectance function and CIE tristimulus values in addition to enhance the color vision contrast. The performances of experimental results show the advantages of our system.