Zhao-Long Xiong

Partially-overlapped viewing zone based integral imaging system with super wide viewing angle

In this paper, we analyze the relationship between viewer and viewing zones of integral imaging (II) system and present a partially-overlapped viewing zone (POVZ) based integral imaging system with a super wide viewing angle. In the proposed system, the viewing angle can be wider than the viewing angle of the conventional tracking based II system. In addition, the POVZ can eliminate the flipping and time delay of the 3D scene as well. The proposed II system has a super wide viewing angle of 120° without flipping effect about twice as wide as the conventional one.

Encrypting three-dimensional information system based on integral imaging and multiple chaotic maps

Abstract. An encrypting three-dimensional (3-D) information system based on integral imaging (II) and multiple chaotic maps is proposed. In the encrypting process, the elemental image array (EIA) which represents spatial and angular information of the real 3-D scene is picked up by a microlens array. Subsequently, R, G, and B color components decomposed by the EIA are encrypted using multiple chaotic maps. Finally, these three encrypted components are interwoven to obtain the cipher information. The decryption process implements the reverse operation of the encryption process for retrieving the high-quality 3-D images. Since the encrypted EIA has the data redundancy property due to II, and all parameters of the pickup part are the secret keys of the encrypting system, the system sensitivity on the changes of the plaintext and secret keys can be significantly improved. Moreover, the algorithm based on multiple chaotic maps can effectively enhance the security. A preliminary experiment is carried out, and the experimental results verify the effectiveness, robustness, and security of the proposed system.

Multiple Orthographic Frustum Combing for Real-Time Computer-Generated Integral Imaging System

In this paper, we propose a computer-generated integral imaging (CGII) method called multiple orthographic frustum combining (MOFC), in which an elemental image array (EIA) can be generated by rendering a 3-D scene with one-shot orthographic projection using combing multiple orthographic frustum. The proposed MOFC method exploits the programmability of graphic processing unit to improve the computational efficiency. The experimental results show that the proposed method can achieve real-time computational speed for generating ultra high-definition (3840 ×2160) EIA.

Active integral imaging system based on multiple structured light method

In this paper, we simplify the equipments for integral imaging (II) pickup and implement an active II system based on multiple structured light (MSL) method. In the active II system, the complete three-dimensional (3D) shape of the 3D scene can be reconstructed, and the tunable parallaxes can be generated without occlusions. Therefore, the high-quality 3D images can be displayed efficiently by the II. We also use the Compute Unified Device Architecture implementing the processing algorithms in graphics processing unit. The experimental results demonstrate the effectiveness of the MSL method for the II pickup and the acceleration for the elemental image array generation. Especially, the proposed method is suitable for the real scene with high precision.

Real-time integral imaging pickup system using camera array

Three-dimensional (3D) information acquirement in integral imaging (II) is becoming popular with the development of inexpensive digital image sensors. In this study, we present a real-time II pickup system in which multiple video streams are recorded, compressed, transmitted, and synthesized for II display. The system consists of an 8×8 network camera array, three Gigabit Ethernet switches, a single PC, and an II display. With the help of multi-thread technology, multi-view video streams from the network camera array are first captured in real-time. Then, we adopt camera array calibration and image alignment methods based on planar parallax to achieve good image quality. Finally, the aligned video streams are interweaved to synthesize the elemental image array (EIA) for the II display. We also present a remapping algorithm to accelerate the generation of the EIA. In the remapping algorithm, the mapping matrices from original parallaxes to the EIA are directly calculated. Therefore, the camera array calibration process, the parallax alignment process and the synthesizing process are simplified into a simple remapping operation. The video stream processing is fully performed on a graphics processing unit (GPU). Our proposed system achieves high-quality II video rendering at up to 37fps depending on rendering parameters. Experimental results verify the feasibility of the proposed system and high-quality EIAs synthesized from dynamic 3D scene.

Optical encryption of three-dimensional information based on integral imaging and ptychography

In this paper, we propose an optical method based on integral imaging(II) and ptychography to encrypt threedimensional( 3D) information with simple architecture. The 3D scene plaintext is encrypted by a camera array and double-random phase masks via ptychography to generate a series of diffraction intensity patterns as ciphertexts. Then, the decrypting process with ptychographic iteration and II reconstruction is employed to retrieve high-quality 3D images. Since scanning light probes and parameters of II can serve as secret keys that enlarge the key space, and elemental image array generated by the II pickup has redundancy property, the security of encryption scheme can be improved significantly. Also, the decrypted 3D images in our proposed method have high-quality. Preliminary experiments are carried out, and the results demonstrate the feasibility and robustness of our proposed method. Especially, this research is suitable for real large-size 3D scene.

Dual-Projection Based High-Precision Integral Imaging Pickup System

In this paper, a high-precision integral imaging (II) pickup system for the real scene is proposed. The dual-projection optical pickup method is utilized to obtain the elemental image array for the II display. The proposed method is robust to the position deviations of the projectors and camera. The calibration of the camera is simplified. Furthermore, the pickup of the II is not limited by the complex optical and mechanical structures. Experimental results show that the proposed system can generate the continuous and tunable parallaxes. With the proposed II pickup and display system, the high-quality 3D images for the real scene can be reconstructed efficiently.

Nonunified integral imaging elemental image array generation method based on selective pixel sampling algorithm

We propose a method based on the selective pixel sampling algorithm to generate a nonunified integral imaging (II) elemental image array (EIA) with reduced moiré patterns at a low rendering cost and high three-dimensional (3D) resolution. In the proposed method, the redundant 3D information is captured for the nonunified pixel arrangement of elemental images, and the moiré patterns are constrained by the constraint equations. The nonunified EIAs corresponding information is mapped from the obtained 3D information based on the selective pixel sampling algorithm. Appropriate experiments are carried out, and the experimental results show that the proposed method can increase the 3D display quality of the reconstructed 3D images in the II display and reduce rendering costs markedly in the generation of ultra-high-definition EIA.