This paper presents a novel method for 2D and 3D shape matching that is insensitive to articulation. It uses the eccentricity transform, which is based on the computation of geodesic distances. Geodesic distances computed over a 2D or 3D shape are articulation insensitive. The eccentricity transform considers the length of the longest geodesics. Histograms of the eccentricity transform characte...

We investigate a pseudo-seismic approach based on the so-called inverse Q-transform as an alternative way of processing transient electromagnetic (TEM) data. This technique transforms the diffusive TEM response into that of propagating waves obeying the standard wave-equation. These transformed data can be input into standard seismic migration schemes with the potential of giving higher resolut...

In image processing, efficiency term refers to the ability in capturing significant information that is sensitive to human visual system with small description. Natural images or scenes that contain intrinsic geometrical structures (contours) are key features of visual information. The existing transform methods like Fourier transformation, wavelets, curvelets, ridgelets etc., have limitations ...

The Fourier transform (FT) nicely represents a wiggling, sinelike data set with only a few peaks in the frequency domain. But while the FT is appropriate for simple stationary data like harmonic waves, complicated signals or images require more elaborate transforms. These transforms must catch fast local variations, detect blurred object contours, differentiate textures, and capture different s...

In this paper we approach the segmentation problem by attempting to incorporate cues such as intensity contrast, region size and texture in the segmentation procedure and derive improved results compared to using individual cues separately. We propose efficient simplification operators and feature extraction schemes, capable of quantifying important characteristics like geometrical complexity, ...

We present the first high-resolution rotational spectrum of an artificial molecular rotary motor. By combining chirped-pulse Fourier transform microwave spectroscopy and supersonic expansions, we captured the vibronic ground-state conformation of a second-generation motor based on chiral, overcrowded alkenes. The rotational constants were accurately determined by fitting more than 200 rotationa...

Symmetries are not only fascinating, but they can also be exploited when designing numerical algorithms and data structures for scientific engineering problems in symmetrical domains. Geometrical symmetries are studied, particularly in the context of so called equivariant operators, which are relevant to a wide range of numerical applications. In these cases, it is possible to exploit the symme...

Digital communication and media sharing have extensively increased in the last couple of years. Research is focused on protecting digital media through copyright protection. The digital media is secured by watermarking. We have developed an image watermarking technique in the frequency domain to hide secure information in the Discrete Cosine Transform (DCT) coefficients of the carrier image. DC...

The Hough Transform is a well-known method for detection of parametrized objects. It is the de facto standard for detecting lines and circles in 2-dimensional data sets. For 3D it has attained little attention so far. Apart from computation costs, the main problem lies in the representation of the accumulator: Usual implementations favor geometrical objects with certain parameters due to uneven...

In this paper we study a class of contour dynamics equations depending on a parameter α for which has been provided numerical evidence of selfsimilar collapse [2]. This family of equations connect the vortex patch problem of the 2D Euler equations (limit α → 0) with the surface quasigeostrophic equation (α = 1). We explore numerically the evolution of these equations, but in order to transform ...