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A virtual reality shooting and display system based on multiple degrees of freedom camera is designed and demonstrated. Three-dimensional scene display and the wide angle display can be achieved easily and quickly through the construction with the proposed system. The range of the viewing scene can be broaden with the image stitching process, and the display in the demonstrated system can achieve the effect of wide angle for applications of image mosaic. In the meantime, the system can realize 3D scene display, which can effectively reduce the complexity of the 3D scene generation, and provide a foundation for adding interactive characteristics for the 3D scene in the future. The system includes an adjustable bracket, computer software, and a virtual reality device. Multiple degrees of freedom of the adjustable bracket are developed to obtain 3D scene source images and mosaic source images easily. 5 degrees of freedom are realized, including rotation, lifting, translation, convergence and pitching. To realize the generation and display of three-dimensional scenes, two cameras are adjusted into a parallel state. With the process of image distortion eliminating and calibration, the image is transferred to the virtual reality device for display. In order to realize wide angle display, the cameras are adjusted into "V" type. The preprocessing includes image matching and fusion to realize image stitching. The mosaic image is transferred for virtual reality display with its image reading and display functions. The wide angle 3D scene display is realized by adjusting different states.

Most current virtual reality (VR) interactions are realized with the hand-held input device which leads to a low degree of presence. There is other solutions using sensors like Leap Motion to recognize the gestures of users in order to interact in a more natural way, but the navigation in these systems is still a problem, because they fail to map the actual walking to virtual walking only with a partial body of the user represented in the synthetic environment. Therefore, we propose a system in which users can walk around in the virtual environment as a humanoid model, selecting menu items and manipulating with the virtual objects using natural hand gestures. With a Kinect depth camera, the system tracks the joints of the user, mapping them to a full virtual body which follows the move of the tracked user. The movements of the feet can be detected to determine whether the user is in walking state, so that the walking of model in the virtual world can be activated and stopped by means of animation control in Unity engine. This method frees the hands of users comparing to traditional navigation way using hand-held device. We use the point cloud data getting from Kinect depth camera to recognize the gestures of users, such as swiping, pressing and manipulating virtual objects. Combining the full body tracking and gestures recognition using Kinect, we achieve our interactive VR system in Unity engine with a high degree of presence.

Virtual view-point generation is one of the key technologies the three-dimensional (3D) display, which renders the new scene image perspective with the existing viewpoints. The three-dimensional scene information can be effectively recovered at different viewing angles to allow users to switch between different views. However, in the process of multiple viewpoints matching, when N free viewpoints are received, we need to match N viewpoints each other, namely matching C 2N = N(N-1)/2 times, and even in the process of matching different baselines errors can occur. To address the problem of great complexity of the traditional virtual view point generation process, a novel and rapid virtual view point generation algorithm is presented in this paper, and actual light field information is used rather than the geometric information. Moreover, for better making the data actual meaning, we mainly use nonnegative tensor factorization(NTF). A tensor representation is introduced for virtual multilayer displays. The light field emitted by an N-layer, M-frame display is represented by a sparse set of non-zero elements restricted to a plane within an Nth-order, rank-M tensor. The tensor representation allows for optimal decomposition of a light field into time-multiplexed, light-attenuating layers using NTF. Finally, the compressive light field of multilayer displays information synthesis is used to obtain virtual view-point by multiple multiplication. Experimental results show that the approach not only the original light field is restored with the high image quality, whose PSNR is 25.6dB, but also the deficiency of traditional matching is made up and any viewpoint can obtained from N free viewpoints.

A-Star (A*) algorithm is a heuristic directed search algorithm to evaluate the cost of moving along a particular path in the search space, which can get the shortest path. Here, path planning between any two points on the map is carried out. The STAGE tool is used to manually add way points on the map and determine their spatial location. The adjacent waypoint with a waypoint ID is connected by the line segment to form the navigation graph. A* algorithm can search the navigation graph to find the shortest path from a starting point to the destination. The A* algorithm can restart searching for path from a certain point, and the complex path can be divided in a plurality of frames. Since the navigation graph consists of the movable space, it is considered the obstacle formed by static objects in the scene, and collision detection between the character and static objects is not considered. A-star algorithm based path planning is experimentally demonstrated on a glasses-free three-dimensional display equipment, so that 3D effect of path finding can be perceived.

Ray Tracing Algorithm is one of the research hotspots in Photorealistic Graphics. It is an important light and shadow technology in many industries with the three-dimensional (3D) structure, such as aerospace, game, video and so on. Unlike the traditional method of pixel shading based on ray tracing, a novel ray tracing algorithm is presented to color and render vertices of the 3D model directly. Rendering results are related to the degree of subdivision of the 3D model. A good light and shade effect is achieved by realizing the quad-tree data structure to get adaptive subdivision of a triangle according to the brightness difference of its vertices. The uniform grid algorithm is adopted to improve the rendering efficiency. Besides, the rendering time is independent of the screen resolution. In theory, as long as the subdivision of a model is adequate, cool effects as the same as the way of pixel shading will be obtained. Our practical application can be compromised between the efficiency and the effectiveness.

Generally, there is a depth of field (DOF) constraint for each kind of auto-stereoscopic display owing to the limited angular resolution, which restricts the depth of display. Device-specific blurring will occur if the depth of object exceeds the DOF boundary. A novel depth-perception preserved three-dimensional (3D) content remapping method is presented to meet the DOF constraint of a target 3D display, by using a nonlinear global operation followed with local depth contrast recovery. Apparent depth is dominated by the distribution of depth contrast rather than an absolute depth value. The framework can be divided into two steps. Firstly, a nonlinear operation is adopted to remap the reference depth map of image to fit into the DOF limitation. Secondly, the depth contrast is recovered by decomposing the reference and remapped depth map into multi-frequency bands, calculating the difference for each band, and then the remapped depth map is used to add the scaled difference of depth map of top levels’ frequency bands. A warping-based view synthesis method is adopted to retarget the light field according to the modified depth map. The experimental results show that the modified light field is sharp while the original perception of depth is maximally preserved.

A high speed synchronized rendering of multi-view video for 8K×4K multi-LCD-spliced three-dimensional (3D) display system based on CUDA is demonstrated. Because the conventional image processing calculation method is no longer applicable to this 3D display system, the CUDA technology is used for 3D image processing to address the problem of low efficiency.The 8K×4K screen is composed of four LCD screens, and accurate segmentation of the scene is carried out to ensure the correct display of 3D contents and a set of controlling and the host software are optimally implemented to make all of the connected processors render 3D videos simultaneously. The system which is based on the master-slave synchronization communication mode and DIBR-CUDA accelerated algorithm is used to realize the high resolution, high frame rate, large size, and wide view angle video rendering for the real-time 3D display. Experimental result shows a stable frame-rate at 30 frame-per-second and the friendly interactive interface can be achieved.

In this paper, an integratable spectrum quantization schema for all-optical analog-to-digital conversion (AOADC) is demonstrated in Ge11.5As24Se64.5 rib film waveguide by slicing the supercontinuum. Owing to the high nonlinearity coefficient of 137.8 W-1m-1, the input pulse peak power are very low which varies from 540 to 900mW and then the broadened spectrum is filtered with an arrayed waveguide grating. As a result, 4-bit quantization resolution along with effective number of bit (ENOB) of 3.985 and a signal-to-noise ratio of 23.99 dB are achieved. It is believed that this proposed schema is suitable for integratable AOADC with low power consumption.

Three-dimensional (3D) displays provides valuable tools for many fields, such as scientific experiment, education, information transmission, medical imaging and physical simulation. Ground based 360° 3D display with dynamic and controllable scene can find some special applications, such as design and construction of buildings, aeronautics, military sand table and so on. It can be utilized to evaluate and visualize the dynamic scene of the battlefield, surgical operation and the 3D canvas of art. In order to achieve the ground based 3D display, the public focus plane should be parallel to the camera’s imaging planes, and optical axes should be offset to the center of public focus plane in both vertical and horizontal directions. Virtual cameras are used to display 3D dynamic scene with Unity 3D engine. Parameters of virtual cameras for capturing scene are designed and analyzed, and locations of virtual cameras are determined by the observer’s eye positions in the observing space world. An interactive dynamic 3D scene for ground based 360° 3D display is demonstrated, which provides high-immersion 3D visualization.

A focus-tunable multi-view holographic three-dimensional (3D) display system with a 10.1 inch 4K liquid crystal device (LCD) panel is presented. In the proposed synthesizing method, computer-generated hologram (CGH) does not require calculations of light diffraction. When multiple rays pass through one point of a 3D image and enter the pupil simultaneously, the eyes can focus on the point according to the depth cue. Benefiting from the holograms, the dense multiple perspective viewpoints of the 3D object are recorded and combined into the CGH in a dense-super-view way, which make two or more rays emitted from the same point in reconstructed light field into the pupil simultaneously. In general, a wavefront is converged to a viewpoint with the amplitude distribution of multi-view images on the hologram plane, and the phase distribution of a spherical wave is converged to the viewpoint. Here, the wavefronts are calculated according to all the multi-view images and then they are summed up to obtain the object wave on the hologram plane. Moreover, the reference light (converging light) is adopted to converge the central diffraction wave from the liquid crystal display (LCD) into a common area in a short view distance. Experimental results shows that the proposed holographic display can regenerate the 3D objects with focus cues: accommodation and retinal blur.

The army's combat training is very important now, and the simulation of the real battlefield environment is of great significance. Two-dimensional information has been unable to meet the demand at present. With the development of virtual reality technology, three-dimensional (3D) simulation of the battlefield environment is possible. In the simulation of 3D battlefield environment, in addition to the terrain, combat personnel and the combat tool ,the simulation of explosions, fire, smoke and other effects is also very important, since these effects can enhance senses of realism and immersion of the 3D scene. However, these special effects are irregular objects, which make it difficult to simulate with the general geometry. Therefore, the simulation of irregular objects is always a hot and difficult research topic in computer graphics. Here, the particle system algorithm is used for simulating irregular objects. We design the simulation of the explosion, fire, smoke based on the particle system and applied it to the battlefield 3D scene. Besides, the battlefield 3D scene simulation with the glasses-free 3D display is carried out with an algorithm based on GPU 4K super-multiview 3D video real-time transformation method. At the same time, with the human-computer interaction function, we ultimately realized glasses-free 3D display of the simulated more realistic and immersed 3D battlefield environment.

In this paper, a dual-core polymer-filled photonic crystal fiber (PCF) is designed for broadband dispersion compensation. Large negative dispersion value from −255 to −823 ps/(nm•km) over the entire C band is achieved. Furthermore, the effective refractive index of the polymer-filled outer core can be well tuned by changing the temperature. This PCF can be used for the dynamical dispersion compensation in wavelength-division-multiplexing (WDM) systems.

A photonic crystal fiber (PCF) with high nonlinearity and flattened dispersion is designed. The structure of PCF is in a hexagon lattice. The larger air holes in the outer rings are used to confine the light field into the core region to enhance the nonlinearity, and the flattened dispersion can be achieved by adjusting the diameters of six smaller air holes in the first ring. By optimizing the sizes of the smaller and larger holes, the PCF can achieve high nonlinearity of 19 W -1 km -1 and low dispersion of 80.96 ps/(nm·km) with the fluctuation dispersion range of 8.49 ps/(nm·km) within the wavelength range of 1400 to 1800 nm. The PCF designed can find important applications in effectively realizing Raman soliton self-frequency shift and generating supercontinuum.

Three-dimensional (3D) display can offer the viewer the realism, which is the candidate for the next-generation imaging. 3D display technology without wearing glasses has become research focus. Currently the display of mobile devices is evolved towards 3D. Mobile devices limit the viewing range due to their mass production as well as the algorithm of relative fixity. Only in the area can be achieved a good viewing experience, which leads to the inconvenience for the viewer. The distance adaptive three-dimensional display based on mobile devices is presented. We analyzed the relationship between the viewing distance and the number of pixels for each viewpoint. Based on the viewing distance detected by sensor, the proposed method automatically adjusts the pixels for each viewpoint to accommodate different viewing distance for mobile portable devices. So the method realizes the adaptive distance between the viewer and the device, The experience of viewing 3D images is also improved, as well as the viewing areas is expanded. The crosstalk and the normalized brightness of the 3D picture after restructuring in different distance are measured. Experimental results show that the algorithm with matching parallax barrier can achieve a good 3D view experience at the different distances.

The noise has a serious effect on the quality of the three-dimensional holographic images reconstructed. A new method is proposed to improve the Burch code and combine it with the three-step phase shifting method to remove the noise. The reconstructed images are with the high contrast and resolution. The three-dimensional reconstruction images are compared with the ones of median filtering and of 20-time intensity superposition method. The performance parameters of three methods are analyzed. The experimental results show that the zero-order light spot, conjugate image and speckle noise are suppressed effectively. The quality of the reconstructed image is noticeably improved.

An arbitrary view synthesis method from 2D-Plus-Depth image for real-time auto-stereoscopic display is presented. Traditional methods use depth image based rendering (DIBR) technology, which is a process of synthesizing “virtual” views of a scene from still or moving images and associated per-pixel depth information. All the virtual view images are generated and then the ultimate stereo-image is synthesized. DIBR can greatly decrease the number of reference images and is flexible and efficient as the depth images are used. However it causes some problems such as the appearance of holes in the rendered image, and the occurrence of depth discontinuity on the surface of the object at virtual image plane. Here, reversed disparity shift pixel rendering is used to generate the stereo-image directly, and the target image won’t generate holes. To avoid duplication of calculation and also to be able to match with any specific three-dimensional display, a selecting table is designed to pick up appropriate virtual viewpoints for auto-stereoscopic display. According to the selecting table, only sub-pixels of the appropriate virtual viewpoints are calculated, so calculation amount is independent of the number of virtual viewpoints. In addition, 3D image warping technology is used to translate depth information to parallax between virtual viewpoints and parallax, and the viewer can adjust the zero-parallax-setting-plane (ZPS) and change parallax conveniently to suit his/her personal preferences. The proposed method is implemented with OPENGL and demonstrated on a laptop computer with a 2.3 GHz Intel Core i5 CPU and NVIDA GeForce GT540m GPU. We got a frame rate 30 frames per second with 4096×2340 video. High synthesis efficiency and good stereoscopic sense can be obtained. The presented method can meet the requirements of real-time ultra-HD super multi-view auto-stereoscopic display.

Because the forming process of transparent surface is entirely artificial, it is difficult to meet the requirements of real-time and high precision. In this paper, the laser monitoring system solution can solve this problem. This system consists of three parts, a laser, a CCD camera, and a computer. The laser beam is injected to the transparent surface, and received by the CCD camera. The image is processed by the computer in real-time. By the changes of laser spot during the forming process, a solution is proposed to calculate the difference between the two spot images, which determines the change of height. The experimental results show that when the transparent surface grows 1mm, the effective axial length changes 30 pixels. After multiple measurements, we obtain the relationship curve between the height of the transparent surface and effective axial length. According to the curve, we calculate the measurement error is 2.725%. The processing speed of computer is also measured. It can process 10 pictures per second. The algorithm reflects superiority in both accuracy and processing speed.

Multiview video coding (MVC) is essential for applications of the auto-stereoscopic three-dimensional displays. However, the computational complexity of MVC encoders is tremendously huge. Fast algorithms are very desirable for the practical applications of MVC. Based on joint early termination , the selection of inter-view prediction and the optimization of the process of Inter8×8 modes by comparison, a fast macroblock(MB) mode selection algorithm is presented. Comparing with the full mode decision in MVC, the experimental results show that the proposed algorithm can reduce up to 78.13% on average and maximum 90.21% encoding time with a little increase in bit rates and loss in PSNR.

It is important to acquire the proper parallax images for the stereoscopic display system. By setting the proper distance between the cameras and the location of the convergent point in this capturing configuration, the displayed 3D scene with the appropriate stereo depth and the expected effect in front of and behind the display screen can be obtained directly. The quantitative relationship between the parallax and the parameters of the capturing configuration with two cameras is presented. The capturing system with multiple cameras for acquiring equal parallaxes between the adjacent captured images for the autostereoscopic display system is also discussed. The proposed methods are demonstrated by the experimental results. The captured images with the calculated parameters for the 3D display system shows the expected results, which can provide the viewers the better immersion and visual comfort without any extra processing.

A fast and accurate TV Logo detection method is presented based on real-time image filtering, noise eliminating and recognition of image features including edge and gray level information. It is important to accurately extract the optical template using the time averaging method from the sample video stream, and then different templates are used to match different logos in separated video streams with different resolution based on the topology features of logos. 12 video streams with different logos are used to verify the proposed method, and the experimental result demonstrates that the achieved accuracy can be up to 99%.

We present recent work and progress on Spectrally Coded Multiplexing (SCM). SCM as a generic multiplexing technique adds new dimension of freedom and provides additional flexibility and channel capability needed for fibre and fibre grating based sensor systems. We show a few examples of our newly developed SCM techniques based on specially designed fibre gratings.

On the basis of non-linear coupled-mode theory, the dispersion relation of a dimensional periodic structure is analyzed and slow Bragg soliton solutions are given. The approximation approach for non-linear coupled-mode theory is studied by assuming adiabatic evolution of the soliton passed through fiber Bragg grating which is apodized by using a hyperbolic tangent apodization function in the middle of the FBG. And in the presence of apodization, the velocity equation of Bragg soliton is found. In this paper, we have simulated the motion tracks and velocities of Bragg solitons, analyzed effects of different parameters on motion track and velocity of Bragg soliton, and obtained different timedisplacement curves and time-velocity curves. It is shown that the final steady velocity of soliton can be found by choosing specifical parameters, thereby, slow Bragg solitons whose propagate velocity through the grating is far lower than the speed of light in glass can obtained. We have presented detailed simulative results that agree with theoretical analysis.

A facilitated fiber Bragg grating detection system for detecting temperature is presented. The scheme uses a processing fiber Bragg grating that is stuck on a cantilever beam and is identical to one used as a sensor to demodulate the temperature signal. A step motor that is controlled by PLC (Programmable Logic Controller) stretches the cantilever beam periodically, and the system of two gratings produces a carrier at this frequency with its phase modulated by the temperature signal applied to the sensing grating. The temperature signal, which is demodulated by this system, is transmitted to PC then processed and displayed in PC. This system’s configuration is simple, sensitivity is high, and cost is low.