Artifact-Free Resolution Enhancement Using a Shearlet Sparsity Prior

Jan Aelterman¹, Hiep Luong¹, Steven Baete², Bart Goossens¹, Aleksandra Pizurica¹, Wilfried Philips¹

Very often, clinicians will zoom in on an MRI image, this means implicitely doing a bilinear, bicubic or sinc interpolation, which gives rise to artifacts. We propose an augmented Lagrangian based reconstruction method, which is akin to compressed sensing MRI reconstruction, to perform this same type of image resolution enhancement. The proposed method dramatically reduces the ringing artifact, while preserving sharpness. We also present a method for estimating the free parameter in the reconstruction formulation in order to accelerate the algorithm.