title: Low Complexity Compression and Speed Enhancement for Optical Scanning Holography.
abstract: In this paper we report a low complexity compression method that is suitable for compact optical scanning holography (OSH) systems with different optical settings. Our proposed method can be divided into 2 major parts. First, an automatic decision maker is applied to select the rows of holographic pixels to be scanned. This process enhances the speed of acquiring a hologram, and also lowers the data rate. Second, each row of down-sampled pixels is converted into a one-bit representation with delta modulation (DM). Existing DM-based hologram compression techniques suffers from the disadvantage that a core parameter, commonly known as the step size, has to be determined in advance. However, the correct value of the step size for compressing each row of hologram is dependent on the dynamic range of the pixels, which could deviate significantly with the object scene, as well as OSH systems with different opical settings. We have overcome this problem by incorporating a dynamic step-size adjustment scheme. The proposed method is applied in the compression of holograms that are acquired with 2 different OSH systems, demonstrating a compression ratio of over two orders of magnitude, while preserving favorable fidelity on the reconstructed images.
authors.affiliation: Department of Electronic Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong.
authors.forename: P W M
authors.initials: PW
authors.lastname: Tsang
authors.affiliation: Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 USA.|Department of Photonics, Feng Chia University, No. 100 Wenhwa Rd., Taichung 407, Taiwan.
authors.forename: T-C
authors.initials: TC
authors.lastname: Poon
authors.affiliation: Department of Photonics, Feng Chia University, No. 100 Wenhwa Rd., Taichung 407, Taiwan.
authors.forename: J-P
authors.initials: JP
authors.lastname: Liu
authors.affiliation: Department of Optical Engineering, Sejong University, 98 Kunja-dong, Kwangjin-gu, Seoul 143-747 South Korea.
authors.forename: T
authors.initials: T
authors.lastname: Kim
authors.affiliation: Department of Optical Engineering, Sejong University, 98 Kunja-dong, Kwangjin-gu, Seoul 143-747 South Korea.
authors.forename: Y S
authors.initials: YS
authors.lastname: Kim