544 research outputs found
3D sunken relief generation from a single image by feature line enhancement
Sunken relief is an art form whereby the depicted shapes are sunk into a given flat plane with a shallow overall depth. In this paper, we propose an efficient sunken relief generation algorithm based on a single image by the technique of feature line enhancement. Our method starts from a single image. First, we smoothen the image with morphological operations such as opening and closing operations and extract the feature lines by comparing the values of adjacent pixels. Then we apply unsharp masking to sharpen the feature lines. After that, we enhance and smoothen the local information to obtain an image with less burrs and jaggies. Differential operations are applied to produce the perceptive relief-like images. Finally, we construct the sunken relief surface by triangularization which transforms two-dimensional information into a three-dimensional model. The experimental results demonstrate that our method is simple and efficient
3D digital relief generation.
This thesis investigates a framework for generating reliefs. Relief is a special kind of sculptured artwork consisting of shapes carved on a surface so as to stand out from the surrounding background. Traditional relief creation is done by hand and is therefore a laborious process. In addition, hand-made reliefs are hard to modify. Contrasted with this, digital relief can offer more flexibility as well as a less laborious alternative and can be easily adjusted. This thesis reviews existing work and offers a framework to tackle the problem of generating three types of reliefs: bas reliefs, high reliefs and sunken reliefs. Considerably enhanced by incorporating gradient operations, an efficient bas relief generation method has been proposed, based on 2D images. An improvement of bas relief and high relief generation method based on 3D models has been provided as well, that employs mesh representation to process the model. This thesis is innovative in describing and evaluating sunken relief
generation techniques. Two types of sunken reliefs have been generated: one is created with pure engraved lines, and the other is generated with smooth height transition between lines. The latter one is more complex to implement,
and includes three elements: a line drawing image provides a input for contour lines; a rendered Lambertian image shares the same light direction of the relief and sets the visual cues and a depth image conveys the height information. These three elements have been combined to generate final sunken reliefs. It is the first time in computer graphics that a method for digital sunken relief
generation has been proposed. The main contribution of this thesis is to have proposed a systematic framework to generate all three types of reliefs. Results of this work can potentially provide references for craftsman, and this work could be beneficial for relief creation in the fields of both entertainment and manufacturing
Computer Assisted Relief Generation - a Survey
In this paper we present an overview of the achievements accomplished to date in the field of computer aided relief
generation. We delineate the problem, classify the different solutions, analyze similarities, investigate the evelopment and review the approaches according to their particular relative strengths and weaknesses. In consequence this survey is likewise addressed to researchers and artists through providing valuable insights into the theory behind the different concepts in this field and augmenting the options available among the methods presented with regard to practical application
Analysis of Bas-Relief Generation Techniques
Simplifying the process of generating relief sculptures has been an interesting topic of research in the past decade. A relief is a type of sculpture that does not entirely extend into three-dimensional space. Instead, it has details that are carved into a flat surface, like wood or stone, such that there are slight elevations from the flat plane that define the subject of the sculpture. When viewed orthogonally straight on, a relief can look like a full sculpture or statue in the respect that a full sense of depth from the subject can be perceived. Creating such a model manually is a tedious and difficult process, akin to the challenges a painter may face when designing a convincing painting.
Like with painting, certain digital tools (3D modeling programs most commonly) can make the process a little easier, but can still take a lot of time to obtain sufficient details. To further simplify the process of relief generation, a sizable amount of research has gone into developing semi-automated processes of creating reliefs based on different types of models. These methods can vary in many ways, including the type of input used, the computational time required, and the quality of the resulting model. The performance typically depends on the type of operations applied to the input model, and usually user-specified parameters to modify
its appearance.
In this thesis, we try to accomplish a few related topics. First, we analyze previous work in the field and briefly summarize the procedures to emphasize a variety of ways to solve the problem. We then look at specific algorithms for generating reliefs from 2D and 3D models. After explaining two of each type, a “basic” approach, and a more sophisticated one, we compare the algorithms based on their difficulty to implement, the quality of the results, and the time to process. The final section will include some more sample results of the previous algorithms, and will suggest possible ideas to enhance their results, which could be applied in continuing research on the topic
Of assembling small sculptures and disassembling large geometry
This thesis describes the research results and contributions that have been achieved
during the author’s doctoral work. It is divided into two independent parts, each
of which is devoted to a particular research aspect.
The first part covers the true-to-detail creation of digital pieces of art, so-called
relief sculptures, from given 3D models. The main goal is to limit the depth of the
contained objects with respect to a certain perspective without compromising the
initial three-dimensional impression. Here, the preservation of significant features
and especially their sharpness is crucial. Therefore, it is necessary to overemphasize
fine surface details to ensure their perceptibility in the more complanate relief.
Our developments are aimed at amending the flexibility and user-friendliness
during the generation process. The main focus is on providing real-time solutions
with intuitive usability that make it possible to create precise, lifelike and
aesthetic results. These goals are reached by a GPU implementation, the use of
efficient filtering techniques, and the replacement of user defined parameters by
adaptive values. Our methods are capable of processing dynamic scenes and allow
the generation of seamless artistic reliefs which can be composed of multiple
elements.
The second part addresses the analysis of repetitive structures, so-called symmetries,
within very large data sets. The automatic recognition of components
and their patterns is a complex correspondence problem which has numerous applications
ranging from information visualization over compression to automatic
scene understanding. Recent algorithms reach their limits with a growing amount
of data, since their runtimes rise quadratically. Our aim is to make even massive
data sets manageable. Therefore, it is necessary to abstract features and to develop
a suitable, low-dimensional descriptor which ensures an efficient, robust, and purposive
search. A simple inspection of the proximity within the descriptor space
helps to significantly reduce the number of necessary pairwise comparisons. Our
method scales quasi-linearly and allows a rapid analysis of data sets which could
not be handled by prior approaches because of their size.Die vorgelegte Arbeit beschreibt die wissenschaftlichen Ergebnisse und Beiträge,
die während der vergangenen Promotionsphase entstanden sind. Sie gliedert sich
in zwei voneinander unabhängige Teile, von denen jeder einem eigenen Forschungsschwerpunkt gewidmet ist.
Der erste Teil beschäftigt sich mit der detailgetreuen Erzeugung digitaler
Kunstwerke, sogenannter Reliefplastiken, aus gegebenen 3D-Modellen. Das Ziel
ist es, die Objekte, abhängig von der Perspektive, stark in ihrer Tiefe zu limitieren,
ohne dass der Eindruck der räumlichen Ausdehnung verloren geht. Hierbei
kommt dem Aufrechterhalten der Schärfe signifikanter Merkmale besondere
Bedeutung zu. Dafür ist es notwendig, die feinen Details der Objektoberfläche
überzubetonen, um ihre Sichtbarkeit im flacheren Relief zu gewährleisten. Unsere
Weiterentwicklungen zielen auf die Verbesserung der Flexibilität und Benutzerfreundlichkeit
während des Enstehungsprozesses ab. Der Fokus liegt dabei
auf dem Bereitstellen intuitiv bedienbarer Echtzeitlösungen, die die Erzeugung
präziser, naturgetreuer und visuell ansprechender Resultate ermöglichen. Diese
Ziele werden durch eine GPU-Implementierung, den Einsatz effizienter Filtertechniken
sowie das Ersetzen benutzergesteuerter Parameter durch adaptive Werte
erreicht. Unsere Methoden erlauben das Verarbeiten dynamischer Szenen und die
Erstellung nahtloser, kunstvoller Reliefs, die aus mehreren Elementen und Perspektiven
zusammengesetzt sein können.
Der zweite Teil behandelt die Analyse wiederkehrender Stukturen, sogenannter
Symmetrien, innerhalb sehr großer Datensätze. Das automatische Erkennen
von Komponenten und deren Muster ist ein komplexes Korrespondenzproblem
mit zahlreichen Anwendungen, von der Informationsvisualisierung über Kompression
bis hin zum automatischen Verstehen. Mit zunehmender Datenmenge
geraten die etablierten Algorithmen an ihre Grenzen, da ihre Laufzeiten quadratisch
ansteigen. Unser Ziel ist es, auch massive Datensätze handhabbar zu machen.
Dazu ist es notwendig, Merkmale zu abstrahieren und einen passenden
niedrigdimensionalen Deskriptor zu entwickeln, der eine effiziente, robuste und
zielführende Suche erlaubt. Eine simple Betrachtung der Nachbarschaft innerhalb
der Deskriptoren hilft dabei, die Anzahl notwendiger paarweiser Vergleiche signifikant
zu reduzieren. Unser Verfahren skaliert quasi-linear und ermöglicht somit
eine rasche Auswertung auch auf Daten, die für bisherige Methoden zu groß waren
Airborne laser scanning raster data visualization
This guide provides an insight into a range of visualization techniques for high-resolution digital elevation models (DEMs). It is provided in the context of investigation and interpretation of various types of historical and modern, cultural and natural small-scale relief features and landscape structures. It also provides concise guidance for selecting the best techniques when looking at a specific type of landscape and/or looking for particular kinds of forms.The three main sections – descriptions of visualization techniques, guidance for selection of the techniques, and visualization tools – accompany examples of visualizations, exemplar archaeological and geomorphological case studies, a glossary of terms, and a list of references and recommendations for further reading. The structure facilitates people of different academic background and level of expertise to understand different visualizations, how to read them, how to manipulate the settings in a calculation, and choose the best suited for the purpose of the intended investigation.A smaller amount of books is also available in hardcover (ISBN 978-961-05-0011-7, 24 EUR).Monografija nudi vpogled v nabor tehnik prikaza visokoločljivih modelov višin. Napisana je v kontekstu preučevanja in interpretacije različnih tipov zgodovinskih in modernih, kulturnih in naravnih majhnih reliefnih oblik. Daje jedrnate napotke za izbiro najboljših tehnik prikaza določenih tipov pokrajine in izrazitih oblik.Tri glavna poglavja – opis tehnik prikazovanja digitalnih modelov višin, napotki za njihovo izbiro in orodja za izračun prikazov –, spremljajo izbrani primeri tipičnih arheoloških in geomorfoloških študij, slovarček pojmov ter seznam literature in priporočenega branja. Posameznikom z različnih znanstvenih področij in z različnim predznanjem o tematiki je struktura v pomoč pri razumevanju različnih tehnik prikazov, kako jih brati, kako izbrati prave nastavitve pri njihovem izračunu in kako prepoznati najbolj primerne za namen zasnovane raziskave
Viewed from above: extracting the built environment from the ancient Purépecha site of Angamuco through development of a new methodology
2019 Fall.Includes bibliographical references.This thesis utilizes commonly used GIS tools to develop a methodology capable of extracting the built environment from the complex topology of the ancient Purépecha site of Angamuco located in Michoacán, Mexico. Unlike lowland areas and coastal regions Angamuco sits upon a volcanic malpaís consisting of rolling hills, small valleys, complex ridgelines, and a multitude of microtopographic features creating a complex physical landscape. This topographically complex landscape creates unique challenges in extracting subtle archaeological features and requires a new methodology to separate the built environment. This new methodology utilizing common GIS tools in a flexible workflow consisting of topographic manipulation, value identification, and analysis preparation. The results of the methodology provides a data set of 87,407 possible archaeological features. These features are all greater than 5m² in area and consist of a wide range of circular to rectilinear, linear, and numerous miscellaneous shaped features throughout the site. The capability of this dataset in further analysis is shown through the application of a density analysis and classification based on the Thinness Ratio to conduct OBIA at the individual feature level. Although, the dataset does require manual clean-up the application of the data to answer certain questions about the urban attributes of the site of Angamuco is valid. Further analysis of this output dataset through GIS can provide detailed answers to questions about urban design for the Purépecha prior to and during the early Empire phase
Remote Sensing and Geosciences for Archaeology
This book collects more than 20 papers, written by renowned experts and scientists from across the globe, that showcase the state-of-the-art and forefront research in archaeological remote sensing and the use of geoscientific techniques to investigate archaeological records and cultural heritage. Very high resolution satellite images from optical and radar space-borne sensors, airborne multi-spectral images, ground penetrating radar, terrestrial laser scanning, 3D modelling, Geographyc Information Systems (GIS) are among the techniques used in the archaeological studies published in this book. The reader can learn how to use these instruments and sensors, also in combination, to investigate cultural landscapes, discover new sites, reconstruct paleo-landscapes, augment the knowledge of monuments, and assess the condition of heritage at risk. Case studies scattered across Europe, Asia and America are presented: from the World UNESCO World Heritage Site of Lines and Geoglyphs of Nasca and Palpa to heritage under threat in the Middle East and North Africa, from coastal heritage in the intertidal flats of the German North Sea to Early and Neolithic settlements in Thessaly. Beginners will learn robust research methodologies and take inspiration; mature scholars will for sure derive inputs for new research and applications
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