디지털 홀로그램의 자동초점 조절 및 재생 알고리즘 연구

Abstract

This thesis concerns developments of reconstruction and autofocusing control algorithm methods by using matlab codes. For these purposes a hologram of USAF 1951 test target is recorded in CCD by using Mach-Zehnder interferometer and Labview software. For the reconstruction of the hologram we used two different reconstruction algorithms such as Fresnel and Fresnel convolution. Frequency image filterings have been done to process hologram reconstruction and used several hologram planes. These hologram distances have been reconstructed by checking the image contrasts of the reconstructed holograms with Fresnel spectrum and threshold absolute gradient methods for autofocusing algorithm developments. From these reconstructed image the absolute sizes of the elements of USAF 1951 test target were compared with those of the measured sizes, which matched well each other. Thus the hologram measuring system is calibrated with this method and we confirmed the developed reconstruction algorithms such as Fresnel and Fresnel convolution are working well. In the future we have plans to develop modified holography microscopy system to measure magnified cell image and characterize the cell.