Effects of quantization in phase-shifting digital holography.
We discuss quantization effects of hologram recording on the quality of reconstructed images in phase-shifting digital holography. We vary bit depths of phase-shifted holograms in both numerical simulation and experiments and then derived the complex amplitude, which is subjected to Fresnel transformation for the image reconstruction. The influence of bit-depth limitation in quantization has been demonstrated in a numerical simulation for spot-array patterns with linearly varying intensities and a continuous intensity object. The objects are provided with uniform and random phase modulation. In experiments, digital holograms are originally recorded at 8 bits and the bit depths are changed to deliver holograms at bit depths of 1 to 8 bits for the image reconstruction. The quality of the reconstructed images has been evaluated for the different quantization levels.
Mills
Godfrey A
GA
Faculty of Engineering, Gunma University, 1-5-1 Tenjin Cho, Kiryu City 376-8515, Gunma, Japan. mills@el.gunma-u.ac.jp
Yamaguchi
Ichirou
I