Fast generation of Fresnel holograms based on multirate filtering

Tsang, P. W. M.; Liu, Jung‐Ping; Cheung, William K.; Poon, Ting‐Chung

doi:10.1364/ao.48.000h23

Cited by 19 publications

(14 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Equation (10) means that if the step size is too small, as reflected by identical past and present samplesê(m, n), it will be magnified by a factor M. Otherwise, the step size will be decreased by a factor N. To avoid granular noise, the step size should be small as it can be dynamically adjusted to larger values according to Eq. (10). The values of M and N are determined empirically to suit the type of signals to be compressed (e.g., speech, music, optical, and holographic signals).…”

Section: Proposed Method: Compressionmentioning

confidence: 99%

“…1,2 The resulting digital holograms can be displayed on electronic accessible devices such as spatial light modulator (SLM) and liquid crystal on silicon (LCOS). 3 Recently, a number of works on fast generation of Fresnel holograms have been reported, [4][5][6][7][8][9][10][11][12][13] suggesting the possible emergence of the three-dimensional video holography systems. Despite the encouraging outcome, there are a number of problems that need to be addressed.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Near computation-free compression of Fresnel holograms based on adaptive delta modulation

Tsang

2011

Opt. Eng

View full text Add to dashboard Cite

Delta modulation (DM) is a classical technique that is generally applied to compress audio signals with a negligible amount of computation. Recently, it has been demonstrated that a similar approach can be applied to provide a moderate degree of compression, and at the same time maintain favorable coding fidelity, in compressing digital Fresnel holograms. The downside of this method is that it is necessary to determine an optimal step size for each of the source holograms through a trial and error process. In this paper we attempt to overcome this problem with adaptive delta modulation (ADM). Being different from the classical DM, the step size in ADM is automatically adjusted according to the intensity variation of the hologram. Experimental evaluation reveals that our proposed method is capable of attaining a compression ratio of 32 times without the need of determining the step size for each hologram. Hence, the proposed technique is useful for any holographic video system where holograms are needed to refresh at video rate. In addition, the proposed technique maintains favorable fidelity on the reconstructed images, and the complexity of both the encoding and decoding process is so small that they can be regarded as near computation-free operations. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

show abstract

Section: Proposed Method: Compressionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Near computation-free compression of Fresnel holograms based on adaptive delta modulation

Tsang

2011

Opt. Eng

View full text Add to dashboard Cite

show abstract

“…(4) and (5) is significantly faster as it only involves a pair of one-dimensional processes, i.e., the formation of the diffraction pattern Oðx; τÞ in each scan plane and the subsequent generation of the overall diffraction pattern Dðx; yÞ. We further noted that Oðx; τÞ can be derived with an economical hardware solution based on field programmable gate array (FPGA) at a throughput of over 100 M pixels per second [25].…”

Section: A Fast Generation Of Fresnel Hologramsmentioning

confidence: 99%

Fast numerical generation and encryption of computer-generated Fresnel holograms

2010

View full text Add to dashboard Cite

In the past two decades, generation and encryption of holographic images have been identified as two important areas of investigation in digital holography. The integration of these two technologies has enabled images to be encrypted with more dimensions of freedom on top of simply employing the encryption keys. Despite the moderate success attained to date, and the rapid advancement of computing technology in recent years, the heavy computation load involved in these two processes remains a major bottleneck in the evolution of the digital holography technology. To alleviate this problem, we have proposed a fast and economical solution which is capable of generating, and at the same time encrypting, holograms with numerical means. In our method, the hologram formation mechanism is decomposed into a pair of onedimensional (1D) processes. In the first stage, a given three-dimensional (3D) scene is partitioned into a stack of uniformed spaced horizontal planes and converted into a set of hologram sublines. Next, the sublines are expanded to a hologram by convolving it with a 1D reference signal. To encrypt the hologram, the reference signal is first convolved with a key function in the form of a maximum length sequence (also known as MLS, or M-sequence). The use of a MLS has two advantages. First, an MLS is spectrally flat so that it will not jeopardize the frequency spectrum of the hologram. Second, the autocorrelation function of an MLS is close to a train of Kronecker delta function. As a result, the encrypted hologram can be decoded by correlating it with the same key that is adopted in the encoding process. Experimental results reveal that the proposed method can be applied to generate and encrypt holograms with a small number of computations. In addition, the encrypted hologram can be decoded and reconstructed to the original 3D scene with good fidelity.

show abstract

“…Tsang et al have extended the concept to the generation of digital Fresnel holograms [51], [52]. The method can be divided into three stages.…”

Section: Sublines and Multirate Filteringmentioning

confidence: 99%

Review on the State-of-the-Art Technologies for Acquisition and Display of Digital Holograms

Tsang

Poon

2016

IEEE Trans. Ind. Inf.

Self Cite

105

View full text Add to dashboard Cite

Optical holography for recording threedimensional (3-D) scenes can be traced back to the early sixties. Since then, the art of holography has been applied in many areas, primarily as a tool for 3-D imaging, processing, and display. Extension of optical holography to other disciplines, such as optical computing and encryption, has been explored, but the scope of development is relatively limited. However, with the rapid advancements in electronics, computing, and material science technologies, most of the optical processes can be substituted with numerical or digital hardware means, thus leading to the emergence of digital holography. A typical digital holography framework can be encapsulated into three major stages, namely the input, processing, and output stages. The input and output stages are gatekeepers connecting the optical and digital worlds, without which the study on digital holography could only be restricted to theoretical and numerical analysis. In the past few decades, numerous research works have been conducted on these two important areas. In this paper, we shall provide a review on the recent development in these two important areas of digital holography. Selected pieces of important and popular works on the acquisition and display of digital holograms will be reported.Index Terms-Computer-generated holography (CGH), digital holography (DH), hologram acquisition, hologram display.

show abstract

Fast generation of Fresnel holograms based on multirate filtering

Cited by 19 publications

References 17 publications

Near computation-free compression of Fresnel holograms based on adaptive delta modulation

Near computation-free compression of Fresnel holograms based on adaptive delta modulation

Fast numerical generation and encryption of computer-generated Fresnel holograms

Review on the State-of-the-Art Technologies for Acquisition and Display of Digital Holograms

Contact Info

Product

Resources

About