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• Multiple Optical Coherence Tomography (OCT) scanned sequences. • The procedure consists in a registration, an average and a filtering of the above OCT images (for this last step the Sampling Kantorovich (SK) algorithm has been used). • The retinal network has been detected by the application of an hybrid segmentation procedure (introduced in the present paper) based on classical Otsu and Phansalkar methods. The aim of this article is to provide an improvement in the reconstruction and visualization of retinal superficial capillary plexus and choriocapillaris images from healthy subjects. The implemented method uses multiple Optical Coherence Tomography (OCT) scanned sequences, performs a registration, an average and a filtering on them using for this last step the Sampling Kantorovich operator (SK). The resulting images are then analyzed with some well known methods in literature to quantitatively evaluate the improvement achieved by the proposed technique. Also fluoroangiography and histological images are introduced as reference to support the reliability and the goodness of the results. [ABSTRACT FROM AUTHOR]

In this paper, we present an application of a reconstruction method to thermographic images employed to analyze the response of a masonry structure under seismic actions. At first the theory of linear multivariate sampling Kantorovich operators is presented. By means of the above operators, we are able to reconstruct images taken from thermographic survey of masonry walls, and enhance their quality. Digital image processing of reconstructed images allows us to identify the mutual arrangement of the blocks (made of stones and/or bricks) and mortar joints inside the wall portion analyzed, and therefore the texture of the masonry. Subsequently, the texture has been used to estimate the equivalent elastic properties of the masonry by means of homogenization techniques. Finally a real-world case-study is analyzed, taking into account the mechanical properties estimated from reconstructed thermographic images and evaluating the structural response in terms of modal analysis. [ABSTRACT FROM AUTHOR]

A large class of multivariate quasi-projection operators is studied. These operators are sampling-type expansions ∑ k ∈ Z d c k (f) ψ (A j · − k) , where A is a matrix and the coefficients c k (f) are associated with a tempered distribution ψ ˜. Error estimates in L p -norm, 2 ≤ p < ∞, are obtained under the so-called weak compatibility conditions for ψ ˜ and ψ , and the Strang-Fix conditions for ψ. Approximation order depends on the smoothness of f and on the order of the compatibility and the Strang-Fix conditions. A number of examples aimed at engineering applications are provided. A special attention is payed to the quasi-projection operators associated with differential-difference expansions. Applications to solving some differential-difference equations are presented. [ABSTRACT FROM AUTHOR]