Fast and reliable estimation of image derivatives is among the most fundamental tasks of low level image processing. Implicit finite differences offer much higher spectral resolving efficiency compared to explicit finite differences while the computational effort increases only slightly. Although implicit finite differences had become known to a general audience of numerical mathematicians and ...

A nonlinear PDE-based image restoration approach is described in this article. The proposed filtering technique is based on a novel fourth-order diffusion model. Unlike many other fourth-order PDE denoising schemes, this nonlinear model provides an optimal trade-off between noise removal, image detail preservation and avoiding of undesired effects. A rigorous mathematical investigation of the w...

This article refers to algorithms based on finite difference schemes for computing mean and affine curvature evolutions of digital images, introduced by Alvarez and Morel [L. Alvarez, J.M. Morel, “Formalization and computational aspects of image analysis”, Acta Numerica, pp. 159, 1994]. We discuss consistency, stability and convergence. Our analysis focuses on some possible choices of the param...

where x = (x1, . . . , xd) ∈ IR , t > 0. HJ equations arise in many practical areas such as differential games, mathematical finance, image enhancement and front propagation. It is well known that solutions of (1) are Lipschitz continuous but derivatives can become discontinuous even if the initial data is smooth. There is a close relation between HJ equations and hyperbolic conservation laws. ...

The present work introduces a 2D medical image retrieval system which employs interest points derived from superpixels in a bags of visual words (BVW) framework. BVWs rely on stable interest points so that the local descriptors can be clustered into representative, discriminative prototypes (the visual words). We show that using the centers of mass of superpixels as interest points yields highe...

In this article, we discuss the question “What Level Set Methods can do for image science”. We examine the scope of these techniques in image science, in particular in image segmentation, and introduce some relevant level set techniques that are potentially useful for this class of applications. We will show that image science demands multi-disciplinary knowledge and flexible but still robust m...

The quality of several colour image difference metrics, pixelwise CIELAB DEab, S-CIELAB, iCAM, Structural Similarity Index, Universal Image Quality and the hue-angle algorithm, have been investigated. These results were compared with the results from a psychophysical experiment in which the perceptual image difference was evaluated. Six original images were reproduced using six different colour...

cantaloupe (cucumis melo) volume was measured using water displacement and image processing methods. the volume determined from image processing method was compared to the volume determined by the water displacement method using the paired samples t-test and the bland-altman approach. the paired samples t-test results showed that the volume determined by image processing method was not signific...

background & aim:  the aim of this study was to evaluate and compare the relationship between body image and quality of life in female patients with breast cancer and healthy women. methods:in the current descriptive, causal, comparative, cross-sectional study, 50 women with breast cancer, referring to the radiotherapy and oncology clinic of imam reza hospital (mashhad, iran) and 50 healthy wom...