Digitization of cultural heritage is of growing importance, both for its preservation for coming generations in the face of looming dangers of natural decay or intentional destruction, and current generations, that in...
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ISBN:
(纸本)9783038681410
Digitization of cultural heritage is of growing importance, both for its preservation for coming generations in the face of looming dangers of natural decay or intentional destruction, and current generations, that increasingly have access to virtual cultural heritage for interactive exploring or scientific analysis. These goals can only be achieved by 3D replicas at reasonable quality and resolution, to come as close as possible to the original. This brings about several challenges to overcome. The challenge of digitizing huge numbers of artefacts is addressed by CultLab3D, the first fully automatic 3D digitization system. Another challenge is the size of objects, as each digitization system is designed for a certain optimum measurement range, leaving which results in loss of quality. Due to optical and mechanical constraints, most systems are not able to faithfully reconstruct objects under a certain size limit in their full geometric detail. Historic coins are one good example, where the deterioration of the surface structure in most cases has progressed to a degree that it not even is perceptible through the fingernail. This challenge is addressed by a modular extension of CultLab3D, the MesoScanner, which is a structured light system that breaks limits in depth resolution through a mechanical lens-shifting extension, allowing physically shifting of fringe patterns on top of the well-known multi-period phase shift method. This is where this work adds two major improvements: First, the signal to noise ratio and thus reconstruction quality has been improved significantly through several algorithmic processing steps. Second, the physical limitation of the measurement range was removed using a 2D actuator steering the object mount, thus allowing for a measurement range at theoretically arbitrary size. This opens up the fully automatic handling of two scenarios: Complete digitization of objects exceeding the measurement range, and unsupervised digitization of large c
Influenced by mouse/pen-based user interfaces, most touchbased object tagging techniques rely mostly on a single interaction point. Once objects are tagged, typically only individual object inclusions/exclusions are p...
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Sketching communicates ideas rapidly through approximate visual images with low overhead (pencil and paper), no need for precision or specialized knowledge, and ease of low-level correction and revision. In contrast, ...
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Sketching communicates ideas rapidly through approximate visual images with low overhead (pencil and paper), no need for precision or specialized knowledge, and ease of low-level correction and revision. In contrast, most 3D computer modeling systems are good at generating arbitrary views of precise 3D models and support high-level editing andrevision. The SKETCH application described in this paper attempts to combine the advantages of each in order to create an environment for rapidly conceptualizing and editing approximate 3D scenes. To achieve this, SKETCH uses simple non-photorealistic rendering and a purely gestural interface based on simplified line drawings of primitives that allows all operations to be specified within the 3D world.
In medical imaging, registration is used to combine images containing information from different modalities or to track treatment effects over time in individual patients. Most registration software packages do not pr...
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Previous work on large image data sets has evolved techniques for handling representations of these data that cache textures of arbitrary, but fixed, size in a limited amount of physical memory for rendering in real-t...
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ISBN:
(纸本)9789898425454
Previous work on large image data sets has evolved techniques for handling representations of these data that cache textures of arbitrary, but fixed, size in a limited amount of physical memory for rendering in real-time. In these approaches the texture data is usually pre-processed and arranged, for instance in a geometry-independent texture clipmap. New technologies in the area of remote sensing generate aerial images in real-time at a high rate in a patchwork-like pattern, and new images may replace previously captured image data. These patchwork-like image data can be used to create a growing texture which is dynamic in the sense that it may be updated in parts and grow in extension in the course of time. For such growing textures, current clipmap techniques are not appropriate. In this paper we introduce the Flexible Clipmap, a technique for incrementally generating a clipmap from a large virtual texture of dynamically changing content and extent. Our technique makes use of a tile-based clipmap approach and a common spatial indexing data structure to provide access to very large growing textures. We present an evaluation of our technique in the context of a remote sensing application which demands real-time rendering of growing texture data.
Manual classification of artefacts is a labor intensive process. Based on 2D images and 3D scans of - for example - ceramic shards, we developed a pattern recognition algorithm which automatically extracts relief feat...
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Besides entertainment, three main areas of application attract industrial interest in virtual environment (VE): marketing, prototyping, and training. Advanced VEs derived from available CAD data or simulation results ...
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Besides entertainment, three main areas of application attract industrial interest in virtual environment (VE): marketing, prototyping, and training. Advanced VEs derived from available CAD data or simulation results still require efficient tools for data preparation, as well as high-end workstations and peripherals. The high costs for these advanced VEs prevent small and medium companies from taking the first steps in this direction.
The trackball metaphor is exploited in many applications where volumetric data needs to be explored. Although it provides an intuitive way to inspect the overall structure of objects of interest, an in-detail inspecti...
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The trackball metaphor is exploited in many applications where volumetric data needs to be explored. Although it provides an intuitive way to inspect the overall structure of objects of interest, an in-detail inspection can be tedious - or when cavities occur even impossible. Therefore we propose a context-aware navigation technique for the exploration of volumetric data. While navigation techniques for polygonal data require information about the rendered geometry, this strategy is not sufficient in the area of volume rendering. Since rendering parameters, e.g., the transfer function, have a strong influence on the visualized structures, they also affect the features to be explored. To compensate for this effect we propose a novel image-based navigation approach for volumetric data. While being intuitive to use, the proposed technique allows the user to perform complex navigation tasks, in particular to get an overview as well as to perform an in-detail inspection without any navigation mode switches. The technique can be easily integrated into raycasting based volume renderers, needs no extra data structures and is independent of the data set as well as the rendering parameters. We will discuss the underlying concepts, explain how to enable the navigation at interactive frame rates using OpenCL, and evaluate its usability as well as its performance.
Widely used pipelines for analyzing high-dimensional data utilize two-dimensional visualizations. These are created, for instance, via t-distributed stochastic neighbor embedding (t-SNE). A crucial element of the t-SN...
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As 3D graphics environment becomes the standards for most computer systems, it is natural to seek a 3D input device for manipulating an object in a 3D virtual world. Unlike 2D interface, however, 3D interface creates ...
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