shearlets

Shearlet-domain task-driven post-processing and filtering of CT noise

While many existing CT noise filtering post-processing techniques optimize minimum mean squared error (MSE)-based quality metrics, it is well-known that the MSE is generally not related to the diagnostic quality of CT images. In medical image quality …

A split-augmented Lagrangian algorithm for spectral factorization of a set of 2D directional filters and application to the design of compact shearlet frames

In this paper, we first briefly review the directional properties of the Dual-Tree complex wavelet transform and we investigate how the directional selectivity of the transform can be increased (i.e., to obtain more than 6 orientations per scale). To …

A primal-dual algorithm for joint demosaicking and deconvolution

In this paper, we present a first-order primal-dual algorithm for tackling the joint demosaicking and deconvolution problem. The proposed algorithm exploits the sparsity of both discrete gradient (TV) and shearlet coefficients as prior knowledge. In …

Iterative CT reconstruction using shearlet-based regularization

In computerized tomography, it is important to reduce the image noise without increasing the acquisition dose. Extensive research has been done into total variation minimization for image denoising and sparse-view reconstruction. However, TV …

Design of a tight frame of 2D shearlets based on a fast non-iterative analysis and synthesis algorithm

The shearlet transform is a recent sibling in the family of geometric image representations that provides a traditional multiresolution analysis combined with a multidirectional analysis. In this paper, we present a fast DFT-based analysis and …

Efficient multiscale and multidirectional representation of 3D Data using the 3D discrete shearlet transform

In recent years, there has been a lot of interest in multiresolution representations that also perform a multidirectional analysis. These representations often yield very sparse representation for multidimensional data. The shearlet representation, …