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1988 | Buch

The Science of Fractal Images

verfasst von: Michael F. Barnsley, Robert L. Devaney, Benoit B. Mandelbrot, Heinz-Otto Peitgen, Dietmar Saupe, Richard F. Voss

herausgegeben von: Heinz-Otto Peitgen, Dietmar Saupe

Verlag: Springer New York

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SUCHEN

Über dieses Buch

This book is based on notes for the course Fractals:lntroduction, Basics and Perspectives given by MichaelF. Barnsley, RobertL. Devaney, Heinz-Otto Peit­ gen, Dietmar Saupe and Richard F. Voss. The course was chaired by Heinz-Otto Peitgen and was part of the SIGGRAPH '87 (Anaheim, California) course pro­ gram. Though the five chapters of this book have emerged from those courses we have tried to make this book a coherent and uniformly styled presentation as much as possible. It is the first book which discusses fractals solely from the point of view of computer graphics. Though fundamental concepts and algo­ rithms are not introduced and discussed in mathematical rigor we have made a serious attempt to justify and motivate wherever it appeared to be desirable. Ba­ sic algorithms are typically presented in pseudo-code or a description so close to code that a reader who is familiar with elementary computer graphics should find no problem to get started. Mandelbrot's fractal geometry provides both a description and a mathemat­ ical model for many of the seemingly complex forms and patterns in nature and the sciences. Fractals have blossomed enormously in the past few years and have helped reconnect pure mathematics research with both natural sciences and computing. Computer graphics has played an essential role both in its de­ velopment and rapidly growing popularity. Conversely, fractal geometry now plays an important role in the rendering, modelling and animation of natural phenomena and fantastic shapes in computer graphics.

Inhaltsverzeichnis

Frontmatter
Chapter 1. Fractals in nature: From characterization to simulation
Abstract
Mandelbrot’s fractal geometry provides both a description and a mathematical model for many of the seemingly complex forms found in nature. Shapes such as coastlines, mountains and clouds are not easily described by traditional Euclidean geometry. Nevertheless, they often possess a remarkable simplifying invariance under changes of magnification. This statistical self-similarity is the essential quality of fractals in nature. It may be quantified by a fractal dimension, a number that agrees with our intuitive notion of dimension but need not be an integer. In Section 1.1 computer generated images are used to build visual intuition for fractal (as opposed to Euclidean) shapes by emphasizing the importance of self-similarity and introducing the concept of fractal dimension. These fractal forgeries also suggest the strong connection of fractals to natural shapes. Section 1.2 provides a brief summary of the usage of fractals in the natural sciences. Section 1.3 presents a more formal mathematical characterization with fractional Brownian motion as a prototype. The distinction between self-similarity and self-affinity will be reviewed. Finally, Section 1.4 will discuss independent cuts, Fourier filtering, midpoint displacement, successive random additions, and the Weierstrass-Mandelbrot random function as specific generating algorithms for random fractals. Many of the mathematical details and a discussion of the various methods and difficulties of estimating fractal dimensions are left to the concluding Section 1.6.
Richard F. Voss
Chapter 2. Algorithms for random fractals
Abstract
For about 200 years now mathematicians have developed the theory of smooth curves and surfaces in two, three or higher dimensions. These are curves and surfaces that globally may have a very complicated structure but in small neighborhoods they are just straight lines or planes. The discipline that deals with these objects is differential geometry. It is one of the most evolved and fascinating subjects in mathematics. On the other hand fractals feature just the opposite of smoothness. While the smooth objects do not yield any more detail on smaller scales a fractal possesses infinite detail at all scales no matter how small they are. The fascination that surrounds fractals has two roots: Fractals are very suitable to simulate many natural phenomena. Stunning pictures have already been produced, and it will not take very long until an uninitiated observer will no longer be able to tell whether a given scene is natural or just computer simulated. The other reason is that fractals are simple to generate on computers. In order to generate a fractal one does not have to be an expert of an involved theory such as calculus, which is necessary for differential geometry. More importantly, the complexity of a fractal, when measured in terms of the length of the shortest computer program that can generate it, is very small.
Dietmar Saupe
Chapter 3. Fractal patterns arising in chaotic dynamical systems
Abstract
Fractals are everywhere. This is no accident, because even the simplest mathematical expressions, when interpreted as dynamical systems, yield fractals. The goal of this chapter is to make this statement precise. We will describe some of the elements of the field of mathematics known as dynamical systems and show how fractals arise quite naturally in this context. We will also present some of the algorithms by which some of these fractal patterns may be generated.
Robert L. Devaney
Chapter 4. Fantastic deterministic fractals
Abstract
The goal of this chapter, which is a continuation of Section 3.3, is to demonstrate how genuine mathematical research experiments open a door to a seemingly inexhaustible new reservoir of fantastic shapes and images. Their aesthetic appeal stems from structures which at the same time are beyond imagination and yet look extremely realistic. Being the result of well defined and mostly very simple mathematical processes — which depend on a few parameters — animations of evolution or metamorphosis of fantastic forms are easy to obtain.
Heinz-Otto Peitgen
Chapter 5. Fractal modeling of real world images
Abstract
Mankind seems to be obsessed with straight lines. I am not sure where it all began, but I like to imagine two Druids overseeing the construction of Stonehenge, and using a piece of stretched string to check the straightness of the edges of those huge stone rectangular blocks, or the path that the light beam from the equinox sun would follow. It was at least an efficient form of quality control; for very little effort by those two Druids it kept the laborers with their eyes sharply on the job.
Michael F. Barnsley
Backmatter
Metadaten
Titel
The Science of Fractal Images
verfasst von
Michael F. Barnsley
Robert L. Devaney
Benoit B. Mandelbrot
Heinz-Otto Peitgen
Dietmar Saupe
Richard F. Voss
herausgegeben von
Heinz-Otto Peitgen
Dietmar Saupe
Copyright-Jahr
1988
Verlag
Springer New York
Electronic ISBN
978-1-4612-3784-6
Print ISBN
978-1-4612-8349-2
DOI
https://doi.org/10.1007/978-1-4612-3784-6