Vascular enhancement with structure preservation from noisy X-ray angiogram images by employing non-local Hessian-based filter

Abstract

Enhancement and denoising are a pair of inverse problems in image processing, how to enhance vascular as well as reducing noise with structure preservation from X-ray angiographic images is important for clinicians to diagnose vascular diseases. In order to complete the task, this paper has proposed a non-local Hessian-based filter (NLHF) including the following key parts: (1) a non-local operator is incorporated into the Hessian matrix to obtain noiseless eigenvalues in a noisy environment. (2) The relation of local image is carried by an exponent function which is used to suppress non-vascular structures around real vascular structures. The quantitative and qualitative results of experiments on both synthetic and real-world clinical X-ray vascular angiograms demonstrate that the proposed NLHF method performs better than the other two Hessian-based methods on vascular enhancement, noise reduction, and structure preservation.