A joint motion & disparity motion estimation technique for 3D integral video compression using evolutionary strategy

3D imaging techniques have the potential to establish a future mass-market in the fields of entertainment and communications. Integral imaging, which can capture true 3D color images with only one camera, has been seen as the right technology to offer stress-free viewing to audiences of more than one person. Just like any digital video, 3D video sequences must also be compressed in order to make it suitable for consumer domain applications. However, ordinary compression techniques found in state-of-the-art video coding standards such as H.264, MPEG-4 and MPEG-2 are not capable of producing enough compression while preserving the 3D clues. Fortunately, a huge amount of redundancies can be found in an integral video sequence in terms of motion and disparity. This paper discusses a novel approach to use both motion and disparity information to compress 3D integral video sequences. We propose to decompose the integral video sequence down to viewpoint video sequences and jointly exploit motion and disparity redundancies to maximize the compression. We further propose an optimization technique based on evolutionary strategies to minimize the computational complexity of the joint motion disparity estimation. Experimental results demonstrate that Joint Motion and Disparity Estimation can achieve over 1 dB objective quality gain over normal motion estimation. Once combined with Evolutionary strategy, this can achieve up to 94% computational cost saving

Pre-processing of integral images for 3-D displays

This paper seeks to explore a method to accurately correct geometric distortions caused during the capture of three dimensional (3-D) integral images. Such distortions are rotational and scaling errors which, if not corrected, will cause banding and moire effects on the replayed image. The method for calculating the angle of deviation in the 3-D Integral Images is based on Hough Transform. It allows detection of the angle necessary for correction of the rotational error. Experiments have been conducted on a number of 3-D integral image samples and it has been found that the proposed method produces results with accuracy of 0.05 deg

Head Tracked Multi User Autostereoscopic 3D Display Investigations

The research covered in this thesis encompasses a consideration of 3D television requirements and a survey of stereoscopic and autostereoscopic methods. This confirms that although there is a lot of activity in this area, very little of this work could be considered suitable for television. The principle of operation, design of the components of the optical system and evaluation of two EU-funded (MUTED & HELIUM3D projects) glasses-free (autostereoscopic) displays is described. Four iterations of the display were built in MUTED, with the results of the first used in designing the second, third and fourth versions. The first three versions of the display use two-49 element arrays, one for the left eye and one for the right. A pattern of spots is projected onto the back of the arrays and these are converted into a series of collimated beams that form exit pupils after passing through the LCD. An exit pupil is a region in the viewing field where either a left or a right image is seen across the complete area of the screen; the positions of these are controlled by a multi-user head tracker. A laser projector was used in the first two versions and, although this projector operated on holographic principles in order to obtain the spot pattern required to produce the exit pupils, it should be noted that images seen by the viewers are not produced holographically so the overall display cannot be described as holographic. In the third version, the laser projector is replaced with a conventional LCOS projector to address the stability and brightness issues discovered in the second version. In 2009, true 120Hz displays became available; this led to the development of a fourth version of the MUTED display that uses 120Hz projector and LCD to overcome the problems of projector instability, produces full-resolution images and simplifies the display hardware. HELIUM3D: A multi-user autostereoscopic display based on laser scanning is also described in this thesis. This display also operates by providing head-tracked exit pupils. It incorporates a red, green and blue (RGB) laser illumination source that illuminates a light engine. Light directions are controlled by a spatial light modulator and are directed to the users’ eyes via a front screen assembly incorporating a novel Gabor superlens. In this work is described that covered the development of demonstrators that showed the principle of temporal multiplexing and a version of the final display that had limited functionality; the reason for this was the delivery of components required for a display with full functionality

Autostereoscopy vs. non-autostereoscopy on the LG Optimus 3D

[ES] El rápido aumento de los dispositivos con características 3D ha permitido una serie de sistemas de entretenimiento nuevos y avanzados para casa, hecho que ha aumentado la demanda de contenidos en 3D: películas en 3D, series en 3D y videojuegos en 3D. Esta tecnología ya se ha aplicado en las pantallas de los teléfonos inteligentes y videoconsolas portátiles. En esta tesina, se realizó un estudio sobre una aplicación para dispositivos Android con dos modos de visualización e interacción con el usuario: con autoestereoscopía y sin autoestereoscopía. Esta aplicación contiene varios objetos, tanto estáticos como dinámicos, en un entorno 3D. Tras realizar la evaluación, los resultados indican el alto grado de interés que tienen los contenidos en 3D para juegos en teléfonos inteligentes. Sin embargo, los problemas de percepción de objetos virtuales en 3D demuestran que esta tecnología todavía necesita mejoras para proporcionar una percepción de profundidad sin pérdida de nitidez en la imagen para que sea adecuada a un amplio grupo de la población.[EN] The rapid increase of 3D capable devices has provided a series of new and advanced home entertainment systems; that indicates a higher number of demands for 3D contents, such as 3D movies, 3D TV series and 3D games. As a result, this technology has been applied already on the displays of Smartphones and handheld video gaming consoles. In this thesis, a study between autostereoscopy and non-autostereoscopy on a Smartphone was carried out by testing a new Android application that provides both visualization modes with user interactions. The new app contains a number of static and dynamic objects in a 3D environment. Evaluation findings indicate that people are interested in 3D game content on Smartphones. However, perception issues of 3D virtual objects and loss of picture quality demonstrate that this technology still needs further improvements before it can become suitable for all groups of people.Kaczmarczyk, KM. (2013). Autostereoscopy vs. non-autostereoscopy on the LG Optimus 3D. http://hdl.handle.net/10251/37109Archivo delegad

Scalable Volumetric Three-dimensional Up-conversion Display Medium

There are many different techniques to display 3D information. However, not many of them are able to provide sufficient depth cues to the observers to sense or feel the images as real three-dimensional objects. Volumetric three-dimensional displays generate images within a real 3D space, so they provide most of the depth cues automatically. This thesis discusses the basic notions required to understand three-dimensional displays. Also discussed are different techniques used to display 3D information and their advantages and disadvantages as well as their current limitations. Several rare-earth doped fluoride crystals that are excited to emit visible light by sequential two photon absorption have been investigated as display medium candidates for static volumetric three dimensional displays. A scalable display medium is suggested to enable large 3D displays. This medium is a dispersion of particles of the rare earth doped fluoride crystals in a refractive index-matched polymer matrix. Detailed experiments are described to prepare such a scalable display medium using a wide variety of polymers. The scattering problem in such a medium was greatly reduced by index-matching the polymer to the crystalline particles. An index-matching condition that optimizes the performance was identified and demonstrated. A potential near-future solution is demonstrated and improvements are suggested

Multimode optical waveguides and lightguides for backplane interconnection and laser illuminated display systems

The aim of the research in this thesis was to design, model, analyse and experimentally test multimode optical waveguides and lightguides for manipulating infrared light for optical backplane interconnections and visible light for laser illuminated display systems. Optical Input/Output Coupling loss at the entry and exit of polymer waveguides depends on optical scattering due to end facet roughness. The input/output coupling loss was measured for different end facet roughness magnitudes and the waveguide surface profiles due to different cutting methods (dicing saw and three milling routers) were compared. The effect of the number of cutting edges on the router, the rotation rate and translation (cutting) speed of the milling routers on the waveguide end facet roughness was established. A further new method for reducing the end facet roughness and so the coupling loss, by curing a layer of core material at the end of the waveguide to cover the roughness fluctuations, was proposed and successfully demonstrated giving the best results reported to date resulting in an improvement of 2.8 dB, even better than those obtained by use of index matching fluid which is impractical in commercial systems. The insertion loss due to waveguide crossing having various crossing angles was calculated using a beam propagation method and ray tracing simulations and compared to experimental measurements. Differences between the results were resolved leading to an understanding that only low order waveguide modes at no more than 6 degrees to the axis were propagating inside the waveguide. Several different optical designs of multimode waveguide for the light engine of a 3D autostereoscopic laser illuminated display system were proposed. Each design performed the functions of laser beam combining, beam shaping and beam homogenizing and the best method was selected, designed, modelled, tested, and implemented in the system. The waveguide material was inspected using spectroscopy to establish the effect of high power optical density on the material performance showing an increased loss particularly in the shorter wavelengths. The effect of waveguide dimensions on the speckle pattern was investigated experimentally and the speckle contrast was reduced to below the threshold of human perception. Speckle contrast was also recorded for the first time along the axis of the 3D display system and normal to it in the viewing area and the speckle characteristics at each stage were investigated. New algorithms for analysing speckle were used and the perceptual ability of human eyes to detect speckle size and contrast were taken into account to minimise perceived speckle patterns. The effect of the core diameter of optical fibres on the speckle pattern was investigated and it was shown that the speckle spot diameter is reduced by increasing the fibre core diameter. Based on this experiment, it was suggested that speckle reduction is more effective if the optical fibre used in the display system has larger diameter. Therefore, a slab waveguide of 1 mm thickness and 20 m width was used for laser beam combining, homogenising and beam shaping and a uniformity of 84% was achieved with just 75 mm length. The speckle was also completely removed at the output of the waveguid

3D Capture and 3D Contents Generation for Holographic Imaging

The intrinsic properties of holograms make 3D holographic imaging the best candidate for a 3D display. The holographic display is an autostereoscopic display which provides highly realistic images with unique perspective for an arbitrary number of viewers, motion parallax both vertically and horizontally, and focusing at different depths. The 3D content generation for this display is carried out by means of digital holography. Digital holography implements the classic holographic principle as a two‐step process of wavefront capture in the form of a 2D interference pattern and wavefront reconstruction by applying numerically or optically a reference wave. The chapter follows the two main tendencies in forming the 3D holographic content—direct feeding of optically recorded digital holograms to a holographic display and computer generation of interference fringes from directional, depth and colour information about the 3D objects. The focus is set on important issues that comprise encoding of 3D information for holographic imaging starting from conversion of optically captured holographic data to the display data format, going through different approaches for forming the content for computer generation of holograms from coherently or incoherently captured 3D data and finishing with methods for the accelerated computing of these holograms