The paper addresses the problem of reconstructing a highresolution image from a set of observation images sampled at a lower rate and subject to additive noise and distortion. The method introduced here is based on our work in multirate optimal filtering, extended to two dimensions. The linear filters used for the reconstruction are periodically spatially-varying (in 2-D) and chosen so that the...

Lingvall, F., 2004. Time-domain Reconstruction Methods for Ultrasonic Array Imaging: A Statistical Approach, 178 pp. Uppsala. ISBN 91-506-1772-9. This thesis is concerned with reconstruction techniques for ultrasonic array imaging based on a statistical approach. The reconstruction problem is posed as the estimation of an image consisting of scattering strengths. To solve the estimation problem...

High Resolution images can be reconstructed from several blurred, noisy and aliased low resolution images using a computational process know as super resolution reconstruction. Super resolution reconstruction is the process of combining several low resolution images into a single higher resolution image. In this paper we concentrate on a special case of super resolution problem where the wrap i...

the pioneer work of image compression/reconstruction based onfuzzy relational equations (icf) and the related works are introduced. theicf regards an original image as a fuzzy relation by embedding the brightnesslevel into [0,1]. the compression/reconstruction of icf correspond to thecomposition/solving inverse problem formulated on fuzzy relational equations.optimizations of icf can be consequ...

Individual projection images in Digital Breast Tomosynthesis (DBT) must be acquired with low levels of radiation, which significantly increases image noise. This work investigates the influence of a denoising algorithm and the Anscombe transformation on the reduction of quantum noise in DBT images. The Anscombe transformation is a variance-stabilizing transformation that converts the signal-dep...

Introduction: This study aims to investigate the influence of background activity variation on image quantification in differently reconstructed PET/CT images. Methods: Measurements were performed on a Discovery-690 PET/CT scanner using a custom-built NEMA-like phantom. A background activity level of 5.3 and 2.6 kBq/ml 18F-FDG were applied. Ima...

Compressive sensing (CS), aiming to reconstruct an image/signal from a small set of random measurements has attracted considerable attentions in recent years. Due to the high dimensionality of images, previous CS methods mainly work on image blocks to avoid the huge requirements of memory and computation, i.e., image blocks are measured with Gaussian random matrices, and the whole images are re...

ABTRACT Background: In nuclear medicine, phantoms are mainly used to evaluate the overall performance of the imaging systems and practically there is no phantom exclusively designed for the evaluation of the software performance.  In this study the Hoffman brain phantom was used for quantitative evaluation of reconstruction techniques. The phantom is modified to acquire t...

Objective(s): The aim of this study is to examine the effect of different smoothing filters on the image quality and SUVmax to achieve the guideline recommended positron emission tomography (PET) image without harmonization. Methods: We used a Biograph mCT PET scanner. A National Electrical Manufacturers Association (NEMA) the International Electrotechnical Commission (IEC) body phantom was fil...

introduction:it is well-recognized that collimator-detector response (cdr) is the main image blurring factor in spect.  in this research, we compensated the images for cdr in molecular spect by using stir reconstruction framework. methods: to assess resolution recovery capability of the stir, a phantom containing five point sources along with a micro derenzo phantom were investigated. influence...