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Research On The Fractal Reversed Problem Of Ifs Modeling Method Of Natural Scenery And Image Compression

Posted on:2001-04-14Degree:MasterType:Thesis
Country:ChinaCandidate:Y H ZhouFull Text:PDF
GTID:2168360002451978Subject:Engineering Graphics
Abstract/Summary:PDF Full Text Request
Fractal geometry is applied in many subjects and fields as a geometry for researching irregular geometrical figure and describing the nature. The research on fractal geometry is limited to how to simulate and generate natural scenery by fractal geometry,while the fractal reversed problem that how to generate fractal object from real natural scenery is seldom researched. The fractal reversed problem plays an important role in actual application such as image modeling~. transmission and communication because it can compress information,reduce information storage space and transmission time.So this paper has practical meaning for the interactive modeling and auto compression of any natural scenery.IFS is an important embranchment of the factal geometry which is Based on the self similarity.It is easy to get the total structural information and shows enormous superority on describing and measuring irregular natural scenery with the basic characteristics that structural details can be magnified unlimited. So it is widely used in the modeling of irregular natural scenery.In this paper,based on the theory of Iterated Function System(IFS),we deeply discuss the fractal reversed problem from two aspects. On the one hand, from the point of interactive acquisition of IFS code, we discuss the modeling of any natural scenery and modeling method of traditional IFS Collage Theorem and simplify its algorithm.Based on the discussion ,we present two new kinds of simple modeling on point of the interrelation of the whole and the part: Part Outline method and Three Points method .Finally,this paper introduces the realization and principle of the modeling and points out the advantages and shortcomings of all these methods through some typical graphics instance. On the other hand, from the point of obtaining image IFS code automatically and compressing information, we discuss deeply the traditional partitional compression algorithm.From the view of preserving image decoding quality and making the fractal compression available,we present a new fractal compression algorithm: Ifs double threshold adaptive multi-level partitioning compression coding and compare it with the traditional method. Finally,under Windows 98,by means of object-oriented programming,a soft system named 搉atural scenerymodeling and reconstructing system?with friendly interface and easy operation is programmed based on Visual C++ 6.0 MFC Library.We realize the traditional methods and our new methods on the computer and make a capability analysis and a result comparsion.Experimental results indicate that the two new interactive modeling methods are not only easier than the traditional method but also have a higher visual degree of reconstruction. Compared to normal short-distance blockbased method , at the nearly same PSNR value, the new fractal image compression algorithm can obtain a higher compression ratio,while encoding time is greatly reduced. For an exquisite image,it can preserve a higher PSNR value by the new method,whereas compress ratio is hardly changed.
Keywords/Search Tags:Fractal, Compression Coding, Collage Theorem, Affine Transformation, Iterated Function System, Adaptive partitioning
PDF Full Text Request
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