edge directional image interpolation using shearlet transform ppt
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In the last years, diverse systems of representation have been proposed that approach scarcely the functions governed by anisotropic characteristics such as edges in the images. Along with the theoretical development of these systems, algorithmic embodiments of the associated transforms were provided. However, one of the most common shortcomings of these frameworks is the failure to provide a unified treatment of the continuous and digital world, ie allowing a digital theory to be a natural digitization of continuum theory. In fact, shearlet systems are the only systems so far that satisfy this property, but still offer optimally scarce approximations of cartoon images. In this chapter, we offer an introduction to digital shearlet theory with a particular focus on a unified treatment of the digital continuum and realm. In our survey we present the implementation of two shearlet transformations, one based on limited band shearlets and the other based on compactly supported shearlets. In addition we will discuss several quantitative measures, which allow an objective comparison with other directional transformations and an objective adjustment of the parameters. The codes for the two transformations presented as well as the framework for quantifying performance are provided in the Matlab ShearLab toolbox. In applied mathematical analysis, shearlets are a multiscale framework that allows efficient coding of anisotropic characteristics in the classes of multivariate problems.
It is now widely recognized that the analysis of the intrinsic geometric characteristics of the underlying image is essential in many applications, including image processing. To achieve this, several schemes of directional image representation have been proposed. In this work the discrete shearlet transformation (DST) is developed which provides an efficient multi-scaled directional representation and shows that the implementation of the transform is constructed in the discrete frame based on a multi resolution analysis (MRA). We evaluate the performance of DST in image reduction and approximation applications. In image approximations, our approach scheme using the DST exceeds the discrete wave transformation (DWT) while the computational cost of our scheme is comparable to the DWT. In addition, in the elimination of images, the DST compares favorably with other transformations existing in the bibliography.