BACKGROUND Denoising with edge preservation is very important in digital x-ray imaging since it may allow us to reduce x-ray dose in human subjects without noticeable degradation of the image quality. In denoising filter design for x-ray imaging, edge preservation as well as noise reduction is of great concern not to lose detailed spatial information for accurate diagnosis. In addition to this,...

An automated multiscale segmentation approach for color images is presented. The scale-space stack is generated using the Perona-Malik diffusion approach and the watershed algorithm is employed to produce the regions at each scale. A minimalinking process by downward projection is carried out over the successive scales, and a region dissimilarity measure—combining scale, contrast, and homogenei...

This is the first study to demonstrate the selectivity of learning for contrast polarity. The finding is the main result of an investigation into the existence of central and peripheral vision mechanisms selective for contrast polarity within the texture-segregation process, using the perceptual learning paradigm in a detection task. Energy models (Malik & Perona, 1990) exclude segregation of t...

Models applied in image processing are often described by nonlinear PDEs in which a good approximation of gradient plays an important role especially in such cases where irregular finite volume grids are used. In image processing, such a situation can occur during a coarsening based on quadtree grids. We present a construction of a deformed quadtree grid in which the connection of representativ...

Praveen Kumar Malik Member IEEE, Harish Parthasarthy Member IEEE, M P Tripathi  Abstract—Calculating current distribution is a common problem in antenna. It significantly affects the operation of almost all type of antenna. There have been many different methods suggested to derive the equation for impedance and current distribution so far. In this paper, integral equation using numerical tech...

Images secured from an astronomical telescope usually suffer from blur and from interference that scientists refer to as ‘‘noise’’. Therefore, good image restoration technique has become an important tool in astronomical observation. In this paper, we propose a modified anisotropic diffusion scheme to tackle the problem of image restoration in astronomy, especially in the case of nebula images....

The removal of speckle noise in three-dimensional (3D) echocardiography is required for better analysis of the image and proper diagnosis and thus an important step in pre-processing. This paper proposes a new algorithm for removing the speckle noise which utilizes Von Neumann neighborhood concept. The application of three dimensional connectivity theories would reduce the noise to a certain ex...

A Multi-scale Approach to Nonuniform Diffusion Ross T. Whitaker and Stephen M. Pizer Department of Computer Science, University of North Carolina Chapel Hill, NC, 27514 This paper examines a new method of image processing that combines information at multiple scales in order to locate boundaries. This method employs a technique of edge-affected diffusion, where blurring is limited by the presen...

We study a class of numerical schemes for nonlinear diffusion filtering that offers insights on the design of novel wavelet shrinkage rules for isotropic and anisotropic image enhancement. These schemes utilise analytical or semi-analytical solutions to dynamical systems that result from space-discrete nonlinear diffusion filtering on minimalistic images with 2×2 pixels. We call them locally an...

Let u ∈ BV(Ω) solve the total variation denoising problem with L-squared fidelity and data f . Caselles et al. [Multiscale Model. Simul. 6 (2008), 879–894] have shown the containment H(Ju \Jf ) = 0 of the jump set Ju of u in that of f . Their proof unfortunately depends heavily on the co-area formula, as do many results in this area, and as such is not directly extensible to higher-order, curva...