28,612 research outputs found

    Intuitive and Accurate Material Appearance Design and Editing

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    Creating and editing high-quality materials for photorealistic rendering can be a difficult task due to the diversity and complexity of material appearance. Material design is the process by which artists specify the reflectance properties of a surface, such as its diffuse color and specular roughness. Even with the support of commercial software packages, material design can be a time-consuming trial-and-error task due to the counter-intuitive nature of the complex reflectance models. Moreover, many material design tasks require the physical realization of virtually designed materials as the final step, which makes the process even more challenging due to rendering artifacts and the limitations of fabrication. In this dissertation, we propose a series of studies and novel techniques to improve the intuitiveness and accuracy of material design and editing. Our goal is to understand how humans visually perceive materials, simplify user interaction in the design process and, and improve the accuracy of the physical fabrication of designs. Our first work focuses on understanding the perceptual dimensions for measured material data. We build a perceptual space based on a low-dimensional reflectance manifold that is computed from crowd-sourced data using a multi-dimensional scaling model. Our analysis shows the proposed perceptual space is consistent with the physical interpretation of the measured data. We also put forward a new material editing interface that takes advantage of the proposed perceptual space. We visualize each dimension of the manifold to help users understand how it changes the material appearance. Our second work investigates the relationship between translucency and glossiness in material perception. We conduct two human subject studies to test if subsurface scattering impacts gloss perception and examine how the shape of an object influences this perception. Based on our results, we discuss why it is necessary to include transparent and translucent media for future research in gloss perception and material design. Our third work addresses user interaction in the material design system. We present a novel Augmented Reality (AR) material design prototype, which allows users to visualize their designs against a real environment and lighting. We believe introducing AR technology can make the design process more intuitive and improve the authenticity of the results for both novice and experienced users. To test this assumption, we conduct a user study to compare our prototype with the traditional material design system with gray-scale background and synthetic lighting. The results demonstrate that with the help of AR techniques, users perform better in terms of objectively measured accuracy and time and they are subjectively more satisfied with their results. Finally, our last work turns to the challenge presented by the physical realization of designed materials. We propose a learning-based solution to map the virtually designed appearance to a meso-scale geometry that can be easily fabricated. Essentially, this is a fitting problem, but compared with previous solutions, our method can provide the fabrication recipe with higher reconstruction accuracy for a large fitting gamut. We demonstrate the efficacy of our solution by comparing the reconstructions with existing solutions and comparing fabrication results with the original design. We also provide an application of bi-scale material editing using the proposed method

    Perceptual and Room Acoustical Evaluation of a Computational Efficient Binaural Room Impulse Response Simulation Method

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    A fast and perceptively plausible method for synthesizing binaural room impulse responses (BRIR) is presented. The method is principally suited for application in dynamic and interactive evaluation environments (e. g., for hearing aid development), psychophysics with adaptively changing room reverberation, or simulation and computer games. In order to achieve a low computational cost, the proposed method is based on a hybrid approach. Using the image source model (ISM; Allen and Berkley [J.Acoust. Soc. Am. Vol. 66(4), 1979]), early reflections are computed in a geometrically exact way, taking into account source and listener positions as well as wall absorption and room geometry approximated by a “shoebox”. The ISM is restricted to a low order and the reverberant tail is generated by a feedback delay network (FDN; Jot and Chaigne [Proc. 90th AES Conv., 1991]), which offers the advantages of a low computational complexity on the one hand and an explicit control of the frequency dependent decay characteristics on the other hand. The FDN approach was extended, taking spatial room properties into account such as room dimensions and different absorption characteristics of the walls. Moreover, the listener orientation and position in the room is considered to achieve a realistic spatial reverberant field. Technical and subjective evaluations were performed by comparing measured and synthesized BRIRs for various rooms. Mostly, a high accuracy both for some common room acoustical parameters and subjective sound properties was found. In addition, an analysis will be presented of several methods to include room geometry in the FDN.DFG, FOR 1732, Individualisierte Hörakustik: Modelle, Algorithmen und Systeme für die Sicherstellung der akustischen Wahrnehmung für alle in allen SituationenDFG, EXC 1077/1, Hören für alle: Modelle, Technologien und Lösungsansätze für Diagnostik, Wiederherstellung und Unterstützung des Hören

    High-Quality Evaluation for Invisible Watermarking Based on Discrete Cosine Transform (DCT) and Singular Value Decomposition (SVD)

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    In this research, we propose an innovative approach that integrates Discrete Cosine Transform (DCT) and Singular Value Decomposition (SVD) to enhance the quality and security of digital images. The purpose of this technique is to embed imperceptible watermarks into images, preserving their integrity and authenticity. The integration of DCT allows for an efficient transformation of image data into frequency components, forming the basis for embedding watermarks that are nearly invisible to the human eye. In this context, SVD offers an advantage by separating singular values and corresponding vectors, facilitating a more sophisticated watermarking process. The quality evaluation using metrics such as MSE, PSNR, UQI, and MSSIM demonstrates the effectiveness of this approach. Low average MSE values, ranging from 0.0058 to 0.0064, indicate minimal distortion in the watermarked images. Additionally, high PSNR values, ranging from 67.20 dB to 67.22 dB, affirm the high image quality achieved after watermarking. These results validate that the integration of DCT and SVD provides a high level of security while maintaining optimal visual quality in digital images. This approach is highly relevant and effective in addressing the challenges of image protection in this digital era

    Brand authenticity : meditating authentic experiences through brand communication

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    Brand authenticity is considered as a core element in the contemporary brand management, but its theory and practice are still surrounded with varying point of views and lack of consensus. In the previous academic research, it has been stated that brand authenticity has positive impact on brand equity and overall reputation as people have an innate desire for authenticity. At an increasing rate, consumers are seeking products that resonate with their desire of authenticity and opine that the existence for the real or genuine have been denied from them. Mezcal is a distilled alcoholic beverage produced from fermented agave juice. Mezcal forms a part of Mexican culture and has deeply entwined roots in the country’s history. By researching mezcal brands, the purpose of this study is to describe how brand authenticity can be mediated in brand communication. The purpose is subsequently divided into four sub-questions: 1. What are the strategical level requirements for brand authenticity? 2. What cues implicate brand authenticity? 3. What signs convey brand authenticity? and 4. How the different signs of authenticity can be interpreted? This study aims to arouse relevant and critical ideas about branding by exploring the actual and potential contributions of brand authenticity communication with semiotic perspective. The study was conducted with qualitative mixed method research by combining semiotic content analysis and poetic inquiry. In total of 49 mezcal brands were examined and both visual and textual authenticity cues are collected. Derived from the prior research on brand authenticity, four strategic level requirements are predominant in constructing and maintaining an authentic brand strategy; purpose, genuineness, consistency and product orientation and the cues that implicate brand authenticity are downplaying commercial motives, craftsmanship, heritage and history, artistry and appealing to lifestyle. By evaluating these cues that are communicated through varying signs, the viewer performs unconsciously an assessment of the brand thus either allowing or denying the authenticity. Based on the research, a brand authenticity syntagma-paradigm was formed to better understand the semiotic levels and practices of brand authenticity communication. Evidently, brand authenticity can be communicated in multiple ways in hidden subliminal messages or presented explicitly throughout brand communication. With different brand authenticity signs, it is possible to create rich, multi-dimensional experiences with consumers and resonate with them in deeper levels

    Sub space: Enhancing the spatial awareness of trainee submariners using 3D simulation environments

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    Rapid advancements in computer technology have facilitated the development of practical and economically feasible three dimensional (3D) computer-generated simulation environments that have been utilized for training in a number of different fields. In particular, this development has been heavily influenced by innovations within the gaming industry, where First Person Shooter (FPS) games are often considered to be on the cutting edge of gaming technology in terms of visual fidelity and performance. 3D simulation environments built upon FPS gaming technologies can be used to realistically represent real world places, while also providing a dynamic and responsive experiential based learning environment for trainees. This type of training environment can be utilized effectively when training within the corresponding real world space may not be safe, practical, or economically feasible. This thesis explores the effectiveness of 3D simulation environments based on FPS gaming technologies to enhance the spatial awareness of trainees in unfamiliar real world spaces. The purpose was to identify the characteristics that contribute to effective learning within such environments. In order to identify these characteristics, a model was proposed representing the interrelationships between, and determinant factors of, the concepts of spatial cognition, learning within a simulation environment, and computer-generated 3D environments. The Location and Scenario Training System (LASTS), developed by the Royal Australian Navy, was evaluated to determine whether experience within the LASTS environment could benefit trainee submariners on Collins class submarines. The LASTS environment utilises the Unreal Runtime FPS game engine to provide a realistic representation of the Main Generator Room (MGR) on-board a Collins class submarine. This simulation was used to engage trainees in a simplified exercise based on the location of items relevant to a 12 Point Safety Round performed inside the MGR. Five trainee submariners were exposed to LASTS and then required to conduct the same exercise on-board a Collins class submarine. This mode of learning was compared to traditional non-immersive classroom teaching involving five additional trainee submariners who were also required to complete the same exercise inside the MGR. A mixture of qualitative and quantitative approaches to data collection and analysis was used to ascertain the effectiveness of LASTS as well as the contributing factors to this and learners\u27 perception of the value of the environment. Results indicated that LASTS could be successfully used as a training tool to enhance the spatial awareness of trainee submariners with regard to the MGR on-board a Collins class submarine. LASTS trainees also demonstrated a better spatial understanding of the MGR environment as a result of their experience compared to trainees who were the recipients of traditional classroom based training. The contributing characteristics of the proposed model were also validated with reference to the data gathered from the LASTS case study. This indicated that the model could be utilized in the design of future 3D simulation environments based on gaming technology in order to facilitate effective spatial awareness training

    Virtual Heritage

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    Virtual heritage has been explained as virtual reality applied to cultural heritage, but this definition only scratches the surface of the fascinating applications, tools and challenges of this fast-changing interdisciplinary field. This book provides an accessible but concise edited coverage of the main topics, tools and issues in virtual heritage. Leading international scholars have provided chapters to explain current issues in accuracy and precision; challenges in adopting advanced animation techniques; shows how archaeological learning can be developed in Minecraft; they propose mixed reality is conceptual rather than just technical; they explore how useful Linked Open Data can be for art history; explain how accessible photogrammetry can be but also ethical and practical issues for applying at scale; provide insight into how to provide interaction in museums involving the wider public; and describe issues in evaluating virtual heritage projects not often addressed even in scholarly papers. The book will be of particular interest to students and scholars in museum studies, digital archaeology, heritage studies, architectural history and modelling, virtual environments

    Arts and Cognition: Performance, Criticism and Aesthetics

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    Key characteristics of specular stereo.

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    Because specular reflection is view-dependent, shiny surfaces behave radically differently from matte, textured surfaces when viewed with two eyes. As a result, specular reflections pose substantial problems for binocular stereopsis. Here we use a combination of computer graphics and geometrical analysis to characterize the key respects in which specular stereo differs from standard stereo, to identify how and why the human visual system fails to reconstruct depths correctly from specular reflections. We describe rendering of stereoscopic images of specular surfaces in which the disparity information can be varied parametrically and independently of monocular appearance. Using the generated surfaces and images, we explain how stereo correspondence can be established with known and unknown surface geometry. We show that even with known geometry, stereo matching for specular surfaces is nontrivial because points in one eye may have zero, one, or multiple matches in the other eye. Matching features typically yield skew (nonintersecting) rays, leading to substantial ortho-epipolar components to the disparities, which makes deriving depth values from matches nontrivial. We suggest that the human visual system may base its depth estimates solely on the epipolar components of disparities while treating the ortho-epipolar components as a measure of the underlying reliability of the disparity signals. Reconstructing virtual surfaces according to these principles reveals that they are piece-wise smooth with very large discontinuities close to inflection points on the physical surface. Together, these distinctive characteristics lead to cues that the visual system could use to diagnose specular reflections from binocular information.The work was funded by the Wellcome Trust (grants 08459/Z/07/Z & 095183/Z/10/Z) and the EU Marie Curie Initial Training Network “PRISM” (FP7-PEOPLE-2012-ITN, Agreement: 316746).This is the author accepted manuscript. The final version is available from ARVO via http://dx.doi.org/10.1167/14.14.1
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