Changes between Version 28 and Version 29 of SandBoxPac


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Timestamp:
01/27/09 11:54:29 (16 years ago)
Author:
pacitu
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  • SandBoxPac

    v28 v29  
    2424== Setting up Postgresql == 
    2525 
     26INTRODUCTION 
     27Mathematical morphology (MM) offers a variety of tools for texture char- 
     28acterization, such as granulometry, morphological covariance, orientation 
     29maps, etc. The  
     30rst two in particular have been employed successfully in a 
     31number of texture analysis applications [3, 7, 22, 23]. 
     32More precisely, granulometry is a powerful tool based on the "sieving" 
     33principle, implemented by means of successive openings and/or closings with 
     34structuring elements (SE) of various sizes, hence it is capable of extracting 
     35shape and size characteristics from textures. Morphological covariance on 
     36the other hand, is based on erosions with pairs of points separated by vectors 
     37of various lengths, and provides information on the coarseness, anisotropy 
     38as well as periodicity of its input. 
     39In this paper, we concentrate on these two operators, and speci 
     40cally on 
     41the combined exploitation of their SE variables: size, distance and direction. 
     42Since the original size-only de 
     43nition of pattern spectra [13], these operators 
     44have been extended in various ways (e.g., color, multivariate, attribute based 
     45versions, etc.). Relatively recent applications have explored for instance 
     46the combination of SE shape and size as far as granulometry is concerned 
     47[24,25], hence leading to a feature matrix rather than a vector, that describes 
     48Proceedings of the 8th International Symposium on Mathematical Morphology, 
     49the combined size and shape distribution of its input. As to covariance, the 
     50coupled use of SE pair distance and direction makes it possible to exploit the 
     51anisotropic properties of textures additionally to their periodicity [12, 23]. 
     52Here we investigate the ways of combining the complementary infor- 
     53mation extracted by these two operators (e.g., concatenation, dimension 
     54reduction, etc.), and propose a hybrid of the two, where SE couples are 
     55varied in terms of size, direction as well as distance. The proposed combi- 
     56nation scheme is compared in terms of classi 
     57cation accuracy, against the 
     58standard de 
     59nitions, using the publically available Outex13 color texture 
     60database. The so far obtained experimental results show that it leads to an 
     61improvement over the usual concatenation of feature vectors. 
     62Furthermore, as far as the extension of this operator to color images is 
     63concerned, since MM is based on complete lattice theory, a vector ordering 
     64mechanism becomes necessary. Hence, we propose a weight based reduced 
     65vector ordering, de 
     66ned on the improved HLS (IHLS) color space, designed 
     67speci 
     68cally for the purpose of color texture classi 
     69cation. This approach 
     70makes it possible to optimize, for instance through genetic algorithms, the 
     71weight of each component adaptively, according to the training set under 
     72consideration. 
     73The rest of the paper is organized as follows. Section 2 introduces brie 
     74y 
     75granulometry and covariance, and then elaborates on the combination of 
     76their variables. In Section 3, the problem of extending morphological op- 
     77erators to multivariate images is discussed, and the proposed ordering is 
     78detailed. Next, Section 4 presents the experimental results that have been 
     79obtained with the Outex13 database. Finally, Section 5 is devoted to con- 
     80cluding remarks. 
    2681 
    27 AsdAsd 
    28 SandBox 
     82