13,053 research outputs found
Modeling of evolving textures using granulometries
This chapter describes a statistical approach to classification of dynamic texture images, called parallel evolution functions (PEFs). Traditional classification methods predict texture class membership using comparisons with a finite set of predefined texture classes and identify the closest class. However, where texture images arise from a dynamic texture evolving over time, estimation of a time state in a continuous evolutionary process is required instead. The PEF approach does this using regression modeling techniques to predict time state. It is a flexible approach which may be based on any suitable image features. Many textures are well suited to a morphological analysis and the PEF approach uses image texture features derived from a granulometric analysis of the image. The method is illustrated using both simulated images of Boolean processes and real images of corrosion. The PEF approach has particular advantages for training sets containing limited numbers of observations, which is the case in many real world industrial inspection scenarios and for which other methods can fail or perform badly. [41] G.W. Horgan, Mathematical morphology for analysing soil structure from images, European Journal of Soil Science, vol. 49, pp. 161ā173, 1998. [42] G.W. Horgan, C.A. Reid and C.A. Glasbey, Biological image processing and enhancement, Image Processing and Analysis, A Practical Approach, R. Baldock and J. Graham, eds., Oxford University Press, Oxford, UK, pp. 37ā67, 2000. [43] B.B. Hubbard, The World According to Wavelets: The Story of a Mathematical Technique in the Making, A.K. Peters Ltd., Wellesley, MA, 1995. [44] H. Iversen and T. Lonnestad. An evaluation of stochastic models for analysis and synthesis of gray-scale texture, Pattern Recognition Letters, vol. 15, pp. 575ā585, 1994. [45] A.K. Jain and F. Farrokhnia, Unsupervised texture segmentation using Gabor filters, Pattern Recognition, vol. 24(12), pp. 1167ā1186, 1991. [46] T. Jossang and F. Feder, The fractal characterization of rough surfaces, Physica Scripta, vol. T44, pp. 9ā14, 1992. [47] A.K. Katsaggelos and T. Chun-Jen, Iterative image restoration, Handbook of Image and Video Processing, A. Bovik, ed., Academic Press, London, pp. 208ā209, 2000. [48] M. KĀØoppen, C.H. Nowack and G. RĀØosel, Pareto-morphology for color image processing, Proceedings of SCIA99, 11th Scandinavian Conference on Image Analysis 1, Kangerlussuaq, Greenland, pp. 195ā202, 1999. [49] S. Krishnamachari and R. Chellappa, Multiresolution Gauss-Markov random field models for texture segmentation, IEEE Transactions on Image Processing, vol. 6(2), pp. 251ā267, 1997. [50] T. Kurita and N. Otsu, Texture classification by higher order local autocorrelation features, Proceedings of ACCV93, Asian Conference on Computer Vision, Osaka, pp. 175ā178, 1993. [51] S.T. Kyvelidis, L. Lykouropoulos and N. Kouloumbi, Digital system for detecting, classifying, and fast retrieving corrosion generated defects, Journal of Coatings Technology, vol. 73(915), pp. 67ā73, 2001. [52] Y. Liu, T. Zhao and J. Zhang, Learning multispectral texture features for cervical cancer detection, Proceedings of 2002 IEEE International Symposium on Biomedical Imaging: Macro to Nano, pp. 169ā172, 2002. [53] G. McGunnigle and M.J. Chantler, Modeling deposition of surface texture, Electronics Letters, vol. 37(12), pp. 749ā750, 2001. [54] J. McKenzie, S. Marshall, A.J. Gray and E.R. Dougherty, Morphological texture analysis using the texture evolution function, International Journal of Pattern Recognition and Artificial Intelligence, vol. 17(2), pp. 167ā185, 2003. [55] J. McKenzie, Classification of dynamically evolving textures using evolution functions, Ph.D. Thesis, University of Strathclyde, UK, 2004. [56] S.G. Mallat, Multiresolution approximations and wavelet orthonormal bases of L2(R), Transactions of the American Mathematical Society, vol. 315, pp. 69ā87, 1989. [57] S.G. Mallat, A theory for multiresolution signal decomposition: the wavelet representation, IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 11, pp. 674ā693, 1989. [58] B.S. Manjunath and W.Y. Ma, Texture features for browsing and retrieval of image data, IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 18, pp. 837ā842, 1996. [59] B.S. Manjunath, G.M. Haley and W.Y. Ma, Multiband techniques for texture classification and segmentation, Handbook of Image and Video Processing, A. Bovik, ed., Academic Press, London, pp. 367ā381, 2000. [60] G. Matheron, Random Sets and Integral Geometry, Wiley Series in Probability and Mathematical Statistics, John Wiley and Sons, New York, 1975
Analysing Large Scale Structure: I. Weighted Scaling Indices and Constrained Randomisation
The method of constrained randomisation is applied to three-dimensional
simulated galaxy distributions. With this technique we generate for a given
data set surrogate data sets which have the same linear properties as the
original data whereas higher order or nonlinear correlations are not preserved.
The analysis of the original and surrogate data sets with measures, which are
sensitive to nonlinearities, yields information about the existence of
nonlinear correlations in the data. We demonstrate how to generate surrogate
data sets from a given point distribution, which have the same linear
properties (power spectrum) as well as the same density amplitude distribution.
We propose weighted scaling indices as a nonlinear statistical measure to
quantify local morphological elements in large scale structure. Using
surrogates is is shown that the data sets with the same 2-point correlation
functions have slightly different void probability functions and especially a
different set of weighted scaling indices. Thus a refined analysis of the large
scale structure becomes possible by calculating local scaling properties
whereby the method of constrained randomisation yields a vital tool for testing
the performance of statistical measures in terms of sensitivity to different
topological features and discriminative power.Comment: 10 pages, 5 figures, accepted for publication in MNRA
Differing self-similarity in light scattering spectra: A potential tool for pre-cancer detection
The fluctuations in the elastic light scattering spectra of normal and
dysplastic human cervical tissues analyzed through wavelet transform based
techniques reveal clear signatures of self-similar behavior in the spectral
fluctuations. Significant differences in the power law behavior ascertained
through the scaling exponent was observed in these tissues. The strong
dependence of the elastic light scattering on the size distribution of the
scatterers manifests in the angular variation of the scaling exponent.
Interestingly, the spectral fluctuations in both these tissues showed
multi-fractality (non-stationarity in fluctuations), the degree of
multi-fractality being marginally higher in the case of dysplastic tissues.
These findings using the multi-resolution analysis capability of the discrete
wavelet transform can contribute to the recent surge in the exploration for
non-invasive optical tools for pre-cancer detection.Comment: 13 pages, 14 figure
Comparative performance of airyscan and structured illumination superresolution microscopy in the study of the surface texture and 3D shape of pollen
The visualization of taxonomically diagnostic features of individual pollen grains can be a challenge for many ecologically and phylogenetically important pollen types. The resolution of traditional optical microscopy is limited by the diffraction of light (250 nm), while high resolution tools such as electron microscopy are limited by laborious preparation and imaging workflows. Airyscan confocal superresolution and structured illumination superresolution (SR-SIM) microscopy are powerful new tools for the study of nanoscale pollen morphology and three-dimensional structure that can overcome these basic limitations. This study demonstrates their utility in capturing morphological details below the diffraction limit of light. Using three distinct pollen morphotypes (Croton hirtus, Dactylis glomerata, and Helianthus sp.) and contrast-enhancing fluorescent staining, we were able to assess the effectiveness of the Airyscan and SR-SIM. We further demonstrate that these new superresolution methods can be easily applied to the study of fossil pollen material
A comprehensive overview of the Cold Spot
The report of a significant deviation of the CMB temperature anisotropies
distribution from Gaussianity (soon after the public release of the WMAP data
in 2003) has become one of the most solid WMAP anomalies. This detection
grounds on an excess of the kurtosis of the Spherical Mexican Hat Wavelet
coefficients at scales of around 10 degrees. At these scales, a prominent
feature --located in the southern Galactic hemisphere-- was highlighted from
the rest of the SMHW coefficients: the Cold Spot. This article presents a
comprehensive overview related to the study of the Cold Spot, paying attention
to the non-Gaussianity detection methods, the morphological characteristics of
the Cold Spot, and the possible sources studied in the literature to explain
its nature. Special emphasis is made on the Cold Spot compatibility with a
cosmic texture, commenting on future tests that would help to give support or
discard this hypothesis.Comment: 21 pages, 14 figures. Accepted for publication in the Advances in
Astronomy special issue "Testing the Gaussianity and Statistical Isotropy of
the Universe
- ā¦