Shogo NISHI¹, Kojiro SHIBA³, Kunihiko MORI^2,3, Shigeru NAKAYAMA^2,3 and Sadayuki MURASHIMA³

¹Faculty of Information and Communication Engineering, Osaka Electro-Communication University, 18-8 Hatsu-cho, Neyagawa, Osaka 572-8530, Japan
²Computing and Communications Center, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan
³Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan

(Received November 1, 2004; Accepted May 6, 2005; Revised April 27, 2005)

Fresnel CGH for a three-dimensional (3-D) object is generated by calculating the Fresnel diffraction, but it requires a huge amount of calculation. This is one reason for the difficulty in realizing real-time holography. We propose fast calculation method of computer-generated Fresnel hologram (Fresnel CGH) utilizing distributed parallel processing and array operation. In our method, a projected image with depth information of the 3-D object is prepared to calculate the Fresnel diffraction. The Fresnel diffraction of the projected image is then calculated with depth information by array operation and distributed parallel processing. Parallel processing is realized using JavaSpaces and many standard computers. In our array operation, calculation error in phase distribution on a hologram occurs more than the strict Fresnel diffraction. However, it was confirmed by experiments that the influence of an error can be controlled and ignored. In this paper, our proposed method and some experimental results are shown.

Key words: Fresnel CGH, fast calculation, projected image, array operation, distributed parallel processing