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Showing papers in "IEEE Computer Graphics and Applications in 2002"


Journal ArticleDOI
TL;DR: This work built on another training-based super- resolution algorithm and developed a faster and simpler algorithm for one-pass super-resolution that requires only a nearest-neighbor search in the training set for a vector derived from each patch of local image data.
Abstract: We call methods for achieving high-resolution enlargements of pixel-based images super-resolution algorithms. Many applications in graphics or image processing could benefit from such resolution independence, including image-based rendering (IBR), texture mapping, enlarging consumer photographs, and converting NTSC video content to high-definition television. We built on another training-based super-resolution algorithm and developed a faster and simpler algorithm for one-pass super-resolution. Our algorithm requires only a nearest-neighbor search in the training set for a vector derived from each patch of local image data. This one-pass super-resolution algorithm is a step toward achieving resolution independence in image-based representations. We don't expect perfect resolution independence-even the polygon representation doesn't have that-but increasing the resolution independence of pixel-based representations is an important task for IBR.

2,576 citations


Journal ArticleDOI
TL;DR: The physical principles underlying the variety of approaches to motion tracking are introduced and it is shown that certain methods work quite well for specific applications.
Abstract: This article introduces the physical principles underlying the variety of approaches to motion tracking. Although no single technology will work for all purposes, certain methods work quite well for specific applications.

680 citations


Journal ArticleDOI
TL;DR: The paper discusses Archeoguide which offers personalized augmented reality tours of archaeological sites that uses outdoor tracking, mobile computing, 3D visualization and augmented reality techniques to enhance information presentation, reconstruct ruined sites, and simulate ancient life.
Abstract: The paper discusses Archeoguide which offers personalized augmented reality tours of archaeological sites. It uses outdoor tracking, mobile computing, 3D visualization and augmented reality techniques to enhance information presentation, reconstruct ruined sites, and simulate ancient life.

383 citations


Journal ArticleDOI
TL;DR: A method for discerning fingertip locations in image frames and measuring fingertip trajectories across image frames is introduced and a mechanism for combining direct manipulation and symbolic gestures based on multiple fingertip motions is proposed.
Abstract: Augmented desk interfaces and other virtual reality systems depend on accurate, real-time hand and fingertip tracking for seamless integration between real objects and associated digital information. We introduce a method for discerning fingertip locations in image frames and measuring fingertip trajectories across image frames. We also propose a mechanism for combining direct manipulation and symbolic gestures based on multiple fingertip motions. Our method uses a filtering technique, in addition to detecting fingertips in each image frame, to predict fingertip locations in successive image frames and to examine the correspondences between the predicted locations and detected fingertips. This lets us obtain multiple complex fingertip trajectories in real time and improves fingertip tracking. This method can track multiple fingertips reliably even on a complex background under changing lighting conditions without invasive devices or color markers.

308 citations


Journal ArticleDOI
Fausto Bernardini1, Holly Rushmeier1, Ioana M. Martin1, Joshua Mittleman1, Gabriel Taubin1 
TL;DR: The goal wasn't simply to produce the statue's model but also to provide the art historian with material and tools to enable him to answer his own research questions and to develop scanning technology accessible to other cultural heritage projects both in terms of cost and usability.
Abstract: We present the methodology we used to acquire the data and construct a computer model of Michelangelo's Florentine Pieta with enough detail and accuracy to make it useful in scientific studies. We describe the project to acquire and build the 3D model. The work we describe is unique in that an art historian, not a technologist, conceived and specified the project. Our goal wasn't simply to produce the statue's model but also to provide the art historian with material and tools to enable him to answer his own research questions. The project gave us the opportunity to explore the value of 3D scanning and visualization in a nontechnical discipline, art history. The project's second goal was to develop scanning technology accessible to other cultural heritage projects both in terms of cost and usability.

270 citations


Journal ArticleDOI
TL;DR: This special issue of IEEE Computer Graphics and Applications spotlights both the progress and recent advances in image-based approaches to computer graphics and demonstrates the indelible impact these approaches have had on the field.
Abstract: n the past seven years, the adjective image-based has become a common fixture in the computer graphics vernacular. As a result, we've witnessed an explosion of new and original uses for photographs and other forms of acquired images in computer graphics applications. We can use collections of images to relight scenes, capture the subtle appearance qualities of real-world objects, derive geometric models, and synthesize images from original viewpoints. Not coincidentally, this explosion has occurred in conjunction with the availability of affordable digital photography. This special issue of IEEE Computer Graphics and Applications spotlights both the progress and recent advances in image-based approaches to computer graphics. It brings together a range of diverse points of view and demonstrates the indelible impact these approaches have had on our field. The introduction of image-based approaches exemplifies one of many dramatic yet, in hindsight, obvious departures in computer graphics. The quest for photo-realistic renderings has long been the holy grail of computer graphics. Prior to the introduction of image-based methods, the most popular approach to achieving improved realism was to incorporate more and more knowledge of physics into simulation-based rendering systems. Generally, these improvements came with the costs of increased simulation times and the introduction of new, often difficult to obtain, material parameters. Image-based rendering is a refreshing alternative because it suggests that we might distill the essence of realism from example photographs. Furthermore, it's turned the computational focus away from simulation, toward a more manageable interpolation-based approach. Image-based computer graphics techniques started gaining traction as a result of two important leaps. First was the realization that we could incorporate images as first-class components of an underlying scene representation. This contrasted with the prevailing practice where images played a more subordinate role, most frequently as static texture maps draped over geometry. A second realization was the recognition that we could treat images as actual measurements of both geometric and radiometric information. This new interpretation has proven to be rich with new opportunities, including new approaches to visibility, improved methods for modeling view-dependent variations in the appearance of materials, and the possibility of combining radiant energy measurements from different images to reilluminate scenes. Furthermore, this interpretation of images as measurements has fostered new connections between the computer graphics and computer vision communities, as well as provided new perspectives on the problems of inverse rendering. This special issue demonstrates the wide-ranging impact that image-based approaches have …

211 citations


Journal ArticleDOI
TL;DR: This tutorial shows how image-based lighting can illuminate synthetic objects with measurement of real light, making objects appear as if they're actually in a real world scene.
Abstract: This tutorial shows how image-based lighting can illuminate synthetic objects with measurement of real light, making objects appear as if they're actually in a real world scene.

201 citations


Journal Article
TL;DR: A fast and robust method for tracking a user's hand and multiple fingertips and gesture recognition based on measured fingertip trajectories for augmented desk interface systems, which is particularly advantageous for human-computer interaction (HCI).

170 citations


Journal ArticleDOI
TL;DR: A fully mobile, wearable AR system that combines a vision-based tracker that uses natural landmarks, with an inertial tracker based on silicon micromachined accelerometers and gyroscopes, which recovers the full 6 DOF pose.
Abstract: We've developed a fully mobile, wearable AR system that combines a vision-based tracker (primarily software algorithms) that uses natural landmarks, with an inertial tracker (custom hardware and firmware) based on silicon micromachined accelerometers and gyroscopes. Unlike other vision-based and hybrid systems, both components recover the full 6 DOF pose. Fusing the two tracking subsystems gives us the benefits of both technologies, while the sensors' complementary nature helps overcome sensor-specific deficiencies. Our system is tailored to affordable, lightweight, energy-efficient mobile AR applications for urban environments, especially the historic centers of European cities.

150 citations


Journal Article
TL;DR: This chapter three experiments are presented to model scratching based on analysis of an experienced performer, and investigates the musical fundamentals of scratching, and explains the most common playing-techniques in more detail.
Abstract: distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled \" GNU Free Documentation License \". To scratch means to drag a vinyl record forwards and backwards against the needle on an ordinary turntable along the grooves, not across, though it might sound like it. This way of producing sounds has during the last two decades made the turntable become a popular instrument for both solo and ensemble playing in different musical styles, still mostly in the hip-hop style where Disk Jockeys (DJs) first started to scratch. However, all musical genres seem to be able to adopt the turntables into their instrumental setups. Composers in traditions like rock, metal, pop, disco, jazz, experimental music, film music, contemporary music and numerous others have been experimenting with DJs the past years. Experimental DJs and most hip-hop DJs now frequently call 221 222 The Sounding Object themselves \" turntablists \" , and the music style of scratching and extensive cut-and-paste mixing is called \" turntablism \". These terms, derived from the word turntable, are now generally accepted. It is also generally accepted that a turn-tablist is a musician and that the turntable is to be considered an instrument. The acoustics of scratching has been barely studied until now. On the other end the business market of DJs equipment is quite large. It is therefore interesting to study the phenomenon of turntablism from a scientific point of view. In this chapter three experiments are presented. Aim of these experiments is to model scratching based on analysis of an experienced performer. For this purpose scratching as an expressive musical playing-style is looked at from different views. Experiment 1 investigates the musical fundamentals of scratching , and explains the most common playing-techniques in more detail. Experiment 2 investigates a real performance with aid of sensors on the equipment in order to understand what kinds of problems and parameter variation a model will need to deal with. Experiment 3 investigates what happens to the record that is being scratched, as it is apparent that some heavy damage will be done to the vinyl and this can therefore affect the sound quality. All the experiments shared part of the equipment …

139 citations


Journal ArticleDOI
TL;DR: Focusing on the text content of a set of conference abstracts, the authors can derive 2D visualizations of information spaces that address complexity and automation in visualizations.
Abstract: A cartographic approach to mapping nongeographic information helps to manage graphic complexity in visualizations. It aids domain comprehension by forcing us to use the same cognitive skills we use when viewing geographic maps. The author presents a distinctly cartographic approach to mapping nongeographic information. Focusing on the text content of a set of conference abstracts, we can derive 2D visualizations of information spaces that address complexity and automation.

Journal ArticleDOI
TL;DR: The authors present information visualization techniques based on a glyph metaphor for visually representing textual log information that can be used to identify an attack before an organization incurs damage, loses information, or has its integrity impugned.
Abstract: Attacks and misuses of computer systems are major concerns in today's network-based world. With the growing concern with regard to cyberterrorism there is a need for new tools and techniques to monitor networks and systems for intrusions and misuse. The goal must be to identify an attack before an organization incurs damage, loses information (theft or otherwise), or has its integrity impugned. With today's network-based economic resources, a successful attack will negatively impact consumer confidence and decrease consumers' willingness to make electronic purchases. The authors present information visualization techniques based on a glyph metaphor for visually representing textual log information.

Journal ArticleDOI
TL;DR: High-resolution 3D imaging and modeling is an important application in the heritage field and several demonstration projects conducted in collaboration with museums and conservation agencies are described.
Abstract: High-resolution 3D imaging and modeling is an important application in the heritage field. We describe several demonstration projects conducted in collaboration with museums and conservation agencies.

Journal ArticleDOI
TL;DR: The coarse shape filters that support the 3D, Internet-based search engine ShapeSifter, which aims to locate parts already in production that have a shape similar to a desired new part, are described.
Abstract: This article describes the coarse shape filters that support the 3D, Internet-based search engine ShapeSifter, which aims to locate parts already in production that have a shape similar to a desired new part. The search engine analyzes the target model's shape characteristics and performs a similarity match on the database's contents. Our main challenge is identifying shape metrics that produce effective characterizations of 3D models for similarity comparison. We focus on using three novel convex hull-based indices to carry out a preliminary coarse filtering of candidates prior to more detailed analysis. We also describe the crucial role played by two databases of benchmark objects. Unlike other shape-matching systems, we chose ShapeSifter's architecture (multistep query), 3D representation (triangulated mesh), and implementation (Java3D) to allow deployment online once it matures.

Journal ArticleDOI
TL;DR: This work developed an image-based rendering approach for displaying multiple avatars that takes advantage of the properties of the urban environment and the way a viewer and the avatars move within it to produce fast rendering, based on positional and directional discretization.
Abstract: Populated virtual urban environments are important in many applications, from urban planning to entertainment. At the current stage of technology, users can interactively navigate through complex, polygon-based scenes rendered with sophisticated lighting effects and high-quality antialiasing techniques. As a result, animated characters (or agents) that users can interact with are also becoming increasingly common. However, rendering crowded scenes with thousands of different animated virtual people in real time is still challenging. To address this, we developed an image-based rendering approach for displaying multiple avatars. We take advantage of the properties of the urban environment and the way a viewer and the avatars move within it to produce fast rendering, based on positional and directional discretization. To display many different individual people at interactive frame rates, we combined texture compression with multipass rendering.

Journal ArticleDOI
TL;DR: Using densely arranged cameras, this work has developed a system that can perform processing in real time from image pickup to interactive display, using video sequences instead of static images, at 10 frames per second.
Abstract: Our work targets 3D scenes in motion. In this article, we propose a method for view-dependent layered representation of 3D dynamic scenes. Using densely arranged cameras, we've developed a system that can perform processing in real time from image pickup to interactive display, using video sequences instead of static images, at 10 frames per second. In our system, images on layers are view dependent, and we update both the shape and image of each layer in real time. This lets us use the dynamic layers as the coarse structure of the dynamic 3D scenes, which improves the quality of the synthesized images. In this sense, our prototype system may be one of the first full real-time image -based modelling and rendering systems. Our experimental results show that this method is useful for interactive 3D rendering of real scenes.

Journal ArticleDOI
TL;DR: To minimize problems of information overload, the authors have begun to develop algorithms for information filtering, which automatically restrict the amount of information displayed in augmented reality.
Abstract: The use of augmented reality (AR) techniques can revolutionize the way people interact with unfamiliar environments. By tracking the user's position and orientation, complicated spatial information can be registered against the real world. My colleagues and I are researching the problem of developing mobile AR systems to be worn by individual users operating in large, complicated environments such as cities. However, an urban environment is extremely complicated. It is populated by large numbers of buildings, each of which can have numerous facts stored about it. Therefore, it is easy for a user to experience information overload. This problem is illustrated. To minimize problems of information overload, we have begun to develop algorithms for information filtering. These tools automatically restrict the amount of information displayed.

Journal ArticleDOI
TL;DR: This work has been exploring how augmented reality (AR) technology can create fundamentally new forms of remote collaboration for mobile devices and how this technology could improve the real world experience of doctors.
Abstract: We've been exploring how augmented reality (AR) technology can create fundamentally new forms of remote collaboration for mobile devices AR involves the overlay of virtual graphics and audio on reality Typically, the user views the world through a handheld or head-mounted display (HMD) that's either see-through or overlays graphics on video of the surrounding environment Unlike other computer interfaces that draw users away from the real world and onto the screen, AR interfaces enhance the real world experience For example, with this technology doctors could see virtual ultrasound information superimposed on a patient's body

Journal ArticleDOI
TL;DR: The registration problem for interactive AR applications is addressed, and an efficient solution to real-time camera tracking for scenes that contain planar structures is proposed, which can consider many types of scene with its method.
Abstract: We address the registration problem for interactive AR applications. Such applications require a real-time registration process. Although the registration problem has received a lot of attention in the computer vision community, it's far from being solved. Ideally, an AR system should work in all environments without the need to prepare the scene ahead of time, and users should be able to walk anywhere they want. In the past, several AR systems have achieved accurate and fast tracking and registration, putting dots over objects and tracking the dots with a camera. We can also achieve registration by identifying features in the scene that we can carefully measure for real-world coordinates. However, such methods restrict the system's flexibility. Hence, we need to investigate registration methods that work in unprepared environments and reduce the need to know the objects' geometry in the scene. We propose an efficient solution to real-time camera tracking for scenes that contain planar structures. We can consider many types of scene with our method. We show that our system is reliable and we can use it for real-time applications. We also present results demonstrating real-time camera tracking on indoor and outdoor scenes.

Journal ArticleDOI
TL;DR: A statistical learning algorithm for synthesizing new random instances of natural sounds using a granular method of sonic analysis, which views sound as a series of short, distinct bursts of energy.
Abstract: Natural sounds are complex phenomena because they typically contain a mixture of events localized in time and frequency. Moreover, dependencies exist across different time scales and frequency bands, which are important for proper sound characterization. Historically, acoustical theorists have represented sound in numerous ways. Our research has focused on a granular method of sonic analysis, which views sound as a series of short, distinct bursts of energy. Using that theory, this article presents a statistical learning algorithm for synthesizing new random instances of natural sounds.

Journal ArticleDOI
TL;DR: This article shows how to call on this structure to define common geometrical constructs, ensuring a consistent computational framework, and shows that one can automatically take care of some of the lower level algorithmic aspects without tricks, exceptions, or hidden degenerate cases by using geometric algebra as a language.
Abstract: Every vector space with an inner product has a geometric algebra, whether or not you choose to use it. This article shows how to call on this structure to define common geometrical constructs, ensuring a consistent computational framework. The goal is to show you that this can be done and that it is compact, directly computational, and transcends the dimensionality of subspaces. We do not use geometric algebra to develop new algorithms for graphics, but hope to demonstrate that one can automatically take care of some of the lower level algorithmic aspects, without tricks, exceptions, or hidden degenerate cases by using geometric algebra as a language.

Journal ArticleDOI
TL;DR: This work surveys sound rendering techniques by comparing them to visual image rendering and describes several approaches for performing sound rendering in virtual auditory environments.
Abstract: We survey sound rendering techniques by comparing them to visual image rendering and describe several approaches for performing sound rendering in virtual auditory environments.

Journal ArticleDOI
TL;DR: The authors present a focus+context method that blurs objects based on their relevance (rather than distance) to direct the user's attention.
Abstract: A common feature of information visualization applications, and also other areas, is to direct the user's attention to certain objects. This alerts users to a problem or shows the matching objects in response to a query. Often users also want to quickly understand the information pointed out in the context of the other information and not just see the results. This is one type of the focus+context (F+C) technique, which provides both detailed information of the currently most relevant objects, as well as giving users an idea of the context. The authors present a focus+context method that blurs objects based on their relevance (rather than distance) to direct the user's attention.

Journal ArticleDOI
TL;DR: This work uses an augmented notice board to explain how a homography, between two images of a planar scene, completely determines the relative camera positions, and shows that the homography can also recover pure camera rotations.
Abstract: To realistically integrate 3D graphics into an unprepared environment, camera position must be estimated by tracking natural image features. We apply our technique to cases where feature positions in adjacent frames of an image sequence are related by a homography, or projective transformation. We describe this transformation's computation and demonstrate several applications. First, we use an augmented notice board to explain how a homography, between two images of a planar scene, completely determines the relative camera positions. Second, we show that the homography can also recover pure camera rotations, and we use this to develop an outdoor AR tracking system. Third, we use the system to measure head rotation and form a simple low-cost virtual reality (VR) tracking solution.

Journal ArticleDOI
S. Hsu1, R. Kumar1
TL;DR: The authors present a complete approach for the automated construction of mosaics from images and video using topology inference, local and global alignment, and compositing.
Abstract: The authors present a complete approach for the automated construction of mosaics from images and video using topology inference, local and global alignment, and compositing.

Journal Article
TL;DR: In this paper, the authors present a focus+context method that blurs objects based on their relevance (rather than distance) to direct the user's attention to the most relevant objects.
Abstract: A common feature of information visualization applications, and also other areas, is to direct the user's attention to certain objects. This alerts users to a problem or shows the matching objects in response to a query. Often users also want to quickly understand the information pointed out in the context of the other information and not just see the results. This is one type of the focus+context (F+C) technique, which provides both detailed information of the currently most relevant objects, as well as giving users an idea of the context. The authors present a focus+context method that blurs objects based on their relevance (rather than distance) to direct the user's attention.

Journal ArticleDOI
TL;DR: The system presented, Multiuser Groups for Conceptual Understanding and Prototyping (MUG), serves as the research platform and lets a team of designers-collaborating over the Internet in a shared, multimodal, 3D workspace-model a 3D layout and semantically grounded behavioral description of a product or device.
Abstract: This article presents an approach to collaborative authoring of design semantics within a multiuser 3D environment. Our research unites ideas from traditional engineering design with recent work from the Semantic Web and knowledge engineering community. The system we present, Multiuser Groups for Conceptual Understanding and Prototyping (MUG), serves as our research platform. it lets a team of designers-collaborating over the Internet in a shared, multimodal, 3D workspace-model a 3D layout and semantically grounded behavioral description of a product or device.

Journal Article
TL;DR: An introduction to the elements of geometric algebra, which contains primitives of any dimensionality (rather than just vectors), and an introduction to three of the products of geometricgebra, the geometric product, the inner product, and the outer product.
Abstract: Geometric algebra is a consistent computational framework in which to define geometric primitives and their relationships. This algebraic approach contains all geometric operators and permits specification of constructions in a coordinate-free manner. Thus, the ideas of geometric algebra are important for developers of CAD systems. This paper gives an introduction to the elements of geometric algebra, which contains primitives of any dimensionality (rather than just vectors), and an introduction to three of the products of geometric algebra, the geometric product, the inner product, and the outer product. These products are illustrated by using them to solve simple geometric problems.

Journal ArticleDOI
TL;DR: A linguistic model is presented, which focuses on three levels: morphological, syntactic, and semantic, which survey the impact of product data quality within an extended enterprise framework and present a linguistic model.
Abstract: We survey the impact of product data quality within an extended enterprise framework and present a linguistic model, which focuses on three levels: morphological, syntactic, and semantic.

Journal ArticleDOI
TL;DR: A user study of viewing 3D geometry on large-screen display devices shows that the crispness of a display device (intraframe performance) must be considered along with the speed at which new frames can be computed (interframe performance).
Abstract: This article summarizes a user study of viewing 3D geometry on large-screen display devices. The geometry models the structure of a complex physical object. Our results show that the crispness of a display device (intraframe performance) must be considered along with the speed at which new frames can be computed (interframe performance). It's important to consider crispness from the user's perspective, using values that aren't often published in device specifications. Equally important is the framework for different types of 3D data and the categorization of display technology and techniques.