HOLOGRAPHICS: Combining Holograms with Interactive Computer Graphics

Among all imaging techniques that have been invented throughout the last decades, computer graphics is one of the most successful tools today. Many areas in science, entertainment, education, and engineering would be unimaginable without the aid of 2D or 3D computer graphics. The reason for this success story might be its interactivity, which is an important property that is still not provided efficiently by competing technologies – such as holography. While optical holography and digital holography are limited to presenting a non-interactive content, electroholography or computer generated holograms (CGH) facilitate the computer-based generation and display of holograms at interactive rates [2,3,29,30]. Holographic fringes can be computed by either rendering multiple perspective images, then combining them into a stereogram [4], or simulating the optical interference and calculating the interference pattern [5]. Once computed, such a system dynamically visualizes the fringes with a holographic display. Since creating an electrohologram requires processing, transmitting, and storing a massive amount of data, today’s computer technology still sets the limits for electroholography. To overcome some of these performance issues, advanced reduction and compression methods have been developed that create truly interactive electroholograms. Unfortunately, most of these holograms are relatively small, low resolution, and cover only a small color spectrum. However, recent advances in consumer graphics hardware may reveal potential acceleration possibilities that can overcome these limitations [6]. In parallel to the development of computer graphics and despite their non-interactivity, optical and digital holography have created new fields, including interferometry, copy protection, data storage, holographic optical elements, and display holograms. Especially display holography has conquered several application domains. Museum exhibits often use optical holograms because they can present 3D objects with almost no loss in visual quality. In contrast to most stereoscopic or autostereoscopic graphics displays, holographic images can provide all depth cues—perspective, binocular disparity, motion parallax, convergence, and accommodation—and theoretically can be viewed simultaneously from an unlimited number of positions. Displaying artifacts virtually removes the need to build physical replicas of the original objects. In addition, optical holograms can be used to make engineering, medical, dental, archaeological, and other recordings—for teaching, training, experimentation and documentation. Archaeologists, for example, use optical holograms to archive and investigate ancient artifacts [7,8]. Scientists can use hologram copies to perform their research without having access to the original artifacts or settling for inaccurate replicas. Optical holograms can store a massive amount of information on a thin holographic emulsion. This technology can record and reconstruct a 3D scene with almost no loss in quality. Natural color holographic silver halide emulsion with grain sizes of 8nm is today’s state-of-the-art [14]. Today, computer graphics and raster displays offer a megapixel resolution and the interactive rendering of megabytes of data. Optical holograms, however, provide a terapixel resolution and are able to present an information content in the range of terabytes in real-time. Both are dimensions that will not be reached by computer graphics and conventional displays within the next years – even if Moore’s law proves to hold in future. Obviously, one has to make a decision between interactivity and quality when choosing a display technology for a particular application. While some applications require high visual realism and real-time presentation (that cannot be provided by computer graphics), others depend on user interaction (which is not possible with optical and digital holograms). Consequently, holography and computer graphics are being used as tools to solve individual research, engineering, and presentation problems within several domains. Up until today, however, these tools have been applied separately. The intention of the project which is summarized in this chapter is to combine both technologies to create a powerful tool for science, industry and education. This has been referred to as HoloGraphics. Several possibilities have been investigated that allow merging computer generated graphics and holograms [1]. The goal is to combine the advantages of conventional holograms (i.e. extremely high visual quality and realism, support for all depth queues and for multiple observers at no computational cost, space efficiency, etc.) with the advantages of today’s computer graphics capabilities (i.e. interactivity, real-time rendering, simulation and animation, stereoscopic and autostereoscopic presentation, etc.). The results of these investigations are presented in this chapter

Imaging techniques in conservation

New imaging techniques are increasingly being used within cultural heritage. This paper explores potential uses of such technologies within conservation and implications of their use on object preservation and accessibility. Study of their effects on objects is crucial because their employment is becoming irreplaceable; for example, polynomial texture mapping (PTM) has revealed previously undetectable surface features. In such cases, it is necessary to continue to use the technique to monitor object condition. 3D laser scanning, PTM, and CT scanning are investigated. Case studies are explored to investigate their current role in cultural heritage. The appropriateness of this role and whether it should be expanded is addressed by analysing advantages and disadvantages of the techniques, their feasibility, and risks caused to object preservation and accessibility. The results indicate that the technologies present some advantages over standard digital photography; PTM in particular is found to be an extremely useful, affordable technique. A more established role within conservation, especially for condition assessments, could be worthwhile. Use of the imaging techniques to create models for exhibition can also be advantageous; however, care must be taken to ensure that such models are used to enhance accessibility to original objects and not to replace them

Terrestrial laser scanner for 3D modelling of USQ Toowoomba campus

3D digital model is a virtual representation of the real world and demand for creation of these models is increasing. Various industries recognized the advantages of these types of models. Level of detail can vary for different applications, from low level detail 3D models that can be used in tourism industry, to high level detail 3D models used in construction and engineering. 3D models of built environment provide base for efficient planning of new developments and efficient management of existing buildings and areas. Modelling of 3D models is time consuming task and depends on requirements of the final model as well as on quality of acquired data. Data for 3D modelling can be acquired by utilizing various surveying technologies or by combination of them. Terrestrial Laser Scanner technology allows collection of high amount of high quality data in relatively short time. It is this capability, of collecting data with great detail, which makes this technology appropriate for data collection as a base for 3D model. If this is combined with traditional survey methods spatial certainty of the model is ensured. Although the high amount of data is advantage when creating 3D models, it can present challenge in modelling built environment and this research project will research how the acquired data can be modelled into final 3D model

The characteristics of the CAT to CAD to rapid prototyping system

ThesisComputer Aided Design (CAD), Rapid Prototyping (RP) and Computer Aided Tomography (CAT) technologies were researched. The project entails a unique combination of the abovementioned technologies, which had to be mastered by the author, on local and international terms. Nine software packages were evaluated to determine the modus operandi, required input and final output results. Fifty Rapid Prototyping systems were investigated to determine the strong and weak areas of the various systems, which showed that prototype materials, machine cost and growing time play an essential role. Thirty Reverse Engineering systems were also researched. Six different RE methods were recorded with several commercial systems available. Nineteen case studies were completed by using several different Computer Aided Tomography (CAT) and Magnetic Resonance Imaging (MRI) centers. Each scanning centre has different apparatus and is discussed in detail in the various case studies. The focus of this project is the data transfer of two dimensional CAT scanning data to threedimensional prototypes by using Reverse Engineering (RE) and Rapid Prototyping (RP). It is therefore of cardinal importance that one is familiar and understands the various fields of interest namely Reverse Engineering, Computer Aided Tomography and Rapid Prototyping. Each of these fields will be discussed in detail, with the latest developments in these fields covered as well. Case studies and research performed in the medical field should gain the medical industry's confidence. Constant marketing and publications will ensure that the technology is applied and transferred to the industry. Commercialisation of the technology is of utmost importanc

IR Barcode Reader

BrandWatch Technologies is a company based in Portland, Oregon that seek to detect counterfeit products in the supply chain. BrandWatch has created a taggant material, a physical marker, that can be printed over barcodes or added to the ink used to print the barcodes themselves. This material, while invisible to the naked eye, is detectable using technology that they have developed. BrandWatch enlisted the help of a four man team of Cal Poly Mechanical Engineering students to combine this technology with that of a barcode scanner. The device, capable of scanning barcodes, detecting the presence of the taggant material, and relaying this information to the user is the end result of this project. The device is easily modifiable to request a taggant read or barcode scan first. A user simply has to pull the trigger and is walked through the process of scanning and reading via LCD screen prompts on the back of the handheld device. The data collected (both barcode and the presence of the taggant) is stored in a csv file on a small USB drive on the back of the device. This can easily be removed to transfer the data to a computer at the end of a work day

Application of 3D Laser Scanning to the Preservation of Fort Conger, a Historic Polar Research Base on Northern Ellesmere Island, Arctic Canada

Fort Conger, located in Quttinirpaaq National Park, Ellesmere Island, is a historic landmark of national and international significance. The site is associated with many important Arctic expeditions, including the ill-fated Lady Franklin Bay Expedition of the First International Polar Year and Robert Peary’s attempts to claim the North Pole. Although situated in one of the most remote locations on earth, Fort Conger is currently at risk because of the effects of climate change, weather, wildlife, and human activity. In this paper, we show how 3D laser scanning was used to record cultural features rapidly and accurately despite the harsh conditions present at the site. We discuss how the future impacts of natural processes and human activities can be managed using 3D scanning data as a baseline, how conservation and restoration work can be planned from the resulting models, and how 3D models created from laser scanning data can be used to excite public interest in cultural stewardship and Arctic history.Fort Conger, situé dans le parc national Quttinirpaaq, sur l’île d’Ellesmere, est un lieu historique d’importance nationale et internationale. Ce site est lié à de nombreuses expéditions arctiques importantes, dont l’infortunée expédition de la baie Lady Franklin relevant de la première année polaire internationale et les tentatives de revendication du pôle Nord par Robert Peary. Bien qu’il se trouve dans l’un des endroits les plus éloignés du globe, Fort Conger subit actuellement les risques découlant des effets du changement climatique, des conditions météorologiques, de la faune et de l’activité humaine. Dans cette communication, nous montrons comment un scanneur laser 3D a permis de répertorier les caractéristiques culturelles avec rapidité et précision malgré les conditions difficiles qui ont cours à ce site. Nous discutons de la manière dont les incidences futures des processus naturels et de l’activité humaine peuvent être gérées à l’aide des données 3D comme données de base, comment les travaux de conservation et de restauration peuvent être planifiés à partir des modèles qui en résultent et comment les modèles 3D créés à partir des données de scannage laser peuvent rehausser l’intérêt du grand public à l’égard de la gérance culturelle et de l’histoire de l’Arctique

Large Scale and Complex Structure Grotto Digitalization Using Photogrammetric Method: A Case Study of Cave No. 13 in Yungang Grottoes

3D reconstruction of cultural heritage with large volume and high precision is a technical problem in the field of photogrammetry. This paper studies a high-precision digitalization method for large-volume immovable heritage assets based on photogrammetry and laser scanning. It solves the problem of large-scale aerial triangulation and ensures overall color and geometric consistency while satisfying high-precision modeling of local details. Taking the millimeter accuracy 3D reconstruction project of Cave No. 13 in Yungang Grottoes as an example, we use more than 280,000 arbitrary images to reconstruct the entire cave and verify the effectiveness of the proposed method