3-D Rebuiding Based On Numerical Reconstruction Of Digital Holograms

Nowadays the study of digital holography has focused on the theory and the algorithm o f i mage formation, a s w ell a s h ow to improve the precision and soon. Among, the algorithm of numerical reconstruction is the kernel of digital holography. Hitherto, several algorithms have been presented. According to recording beam path and methods of numerical reconstruction, the algorithms are mainly diversified into convolution method, phase retrieval method, Fresnel transform method, phase shifting method, digital hologram interferometry using wavelength scanning, and frequency-domain transform method. But all the techniques have not precisely obtained the 3-D information rather only the 2-D light field distribution.This dissertation emphatically investigates the algorithm which can realizes 3-D rebuilding of the numerical reconstruction image of a digital hologram. We apply the Depth-from-focus method of computer vision theory to digital holography and successfully realize 3-D rebuilding of numerical reconstruction images. At the same time, we elementarily probe into its application to 3-D shape measurement. This dissertation also obtains some fruits in the following parts. For one thing, we researched the numerical reconstruction of digital holograms in detail. For another, we adopt an approach to capture a digital hologram. We fabricate an off-axis Fresnel hologram recorded on a silver halide emulsion plate with enough resolution for interference fringes and obtain a digital hologram by a scan with high resolution. What's more, we discuss the factors that affect 3-D rebuilding results.This dissertation consists of four chapters. Chapter one sums up the development o f digital holography and reviews some important techniques for 3 -D shape measurement.In chapter two, we talk about the basic theory of digital holography based on optical holography, FFT algorithm, Fresnel diffraction and discuss the reconstruction...