Discriminative wavelet shape descriptors for recognition of 2-D patterns

“…where [6]. So they only extract the global information of image, just are appropriate to the discrimination of two signals with apparent difference.…”

Section: Orthogonal Complex Wavelet Momentsmentioning

confidence: 99%

Combining Wavelet Velocity Moments and Reflective Symmetry for Gait Recognition

Zhao

2005

Advances in Biometric Person Authentication

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Abstract. Gait is a biometric feature and gait recognition has become a challenging problem in computer vision. New wavelet velocity moments have been developed to describe and recognize gait. Wavelet moments are translation, scale and rotation invariant. Wavelet analysis has the trait of multi-resolution analysis, which strengthens the analysis ability to image subtle feature. According with the psychological studies, reflective symmetry features are introduced to help recognition. Combination of wavelet velocity moments and reflective symmetry not only has the characteristic of wavelet moments, but also reflects the person's walking habit of symmetry. Experiments on two databases show the proposed combined features of wavelet velocity moments and reflective symmetry are efficient to describe gait.

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“…The most widely used practical examples of these use moment invariants (Chen and Xie 2011;Fu et al 2005Fu et al , 2007Hu 1962;Li 1992;Ma et al 2011;Pitas 1993;Xu and Li 2008) and shape descriptors obtained by means of orthogonal integral transforms (Fourier, Hadamard, wavelet, etc. ) applied to the border of the observed object (Persoon and Fu 1986;Shen and Ip 1999;Wang et al 2011;Wang et al 2010;Zahn and Roskies 1972). Unfortunately, due to the global nature of these moment invariants, most of the methods based on them are not sensitive to local peculiarities of the image, so they are only able to discriminate satisfactorily among objects with well-developed geometrical or topological differences.…”

Section: Introductionmentioning

confidence: 99%

Improved Imaging and Image Analysis System for Application to Measurement of Small Ice Crystals

Kühn

Grishin

Sloan

2012

Journal of Atmospheric and Oceanic Technology

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Accurate knowledge of ice particle size and shape distribution is required for understanding of atmospheric microphysical processes. While larger ice particles are easily measured with a variety of sensors, the measurement of small ice particles with sizes down to a few micrometers remains challenging. Here the authors report the development of a system that measures the size and shape of small ice particles using a novel combination of high-resolution imaging and high-speed automated image classification. The optical system has a pixel resolution of 0.2 mm and a resolving power of approximately 1 mm. This imaging instrument is integrated into a cryogenic flow tube that allows precise control of experimental conditions. This study also describes an automated method for the high-speed analysis of high-resolution particle images. Each particle is located in the image using a Sobel edge detector, the border is vectorized, and a polygon representing the border is found. The vertices of this polygon are expressed in complex coordinates, and an analytic implementation of Fourier shape descriptors is used for piecewise integration along the edges of the polygon.The authors demonstrate the capabilities of this system in a study of the early-stage growth of ice particles, which are grown for approximately 1 min at fixed temperature and saturated water vapor concentrations in the cryogenic flowtube. Ice particle shapes and size distributions are reported and compared with habit diagrams found in the literature. The capability of the shape recognition system is verified by comparison with manual classification.

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Discriminative wavelet shape descriptors for recognition of 2-D patterns

Cited by 229 publications

References 15 publications

Feature Extraction Based on Wavelet Moments and Moment Invariants in Machine Vision Systems

Feature Extraction Based on Wavelet Moments and Moment Invariants in Machine Vision Systems

Combining Wavelet Velocity Moments and Reflective Symmetry for Gait Recognition

Improved Imaging and Image Analysis System for Application to Measurement of Small Ice Crystals

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