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Efficient Filon-type solution of highly oscillatory physical optics integrals by demodulating complementary error function
, Article IET Microwaves, Antennas and Propagation ; Volume 10, Issue 6 , 2016 , Pages 638-644 ; 17518725 (ISSN) ; Shishegar, A. A ; Sharif University of Technology
Institution of Engineering and Technology
2016
Abstract
In this study, an efficient frequency-independent and error-controllable Filon-type solution of highly oscillatory physical optics (PO) integrals on the quadratic surfaces is presented. In this method first, PO surface integral is decomposed into some analytically solvable integrals and one highly oscillatory integral (HOI) which must be solved numerically. Then, by demodulating complementary error function, the integrand of this HOI is decomposed into an oscillatory part and a slowly varying part (demodulated part). The demodulated part can be easily approximated by various types of basis functions, especially in high frequencies. Therefore, after approximating the demodulated part using...
Developing Robust Image Similarity Measure in Feature Based Image Registration
, M.Sc. Thesis Sharif University of Technology ; Fatemizadeh, Emad (Supervisor)
Abstract
Image registration is an important preprocessing step in analysis of medical images. Detection, Treatment plan, disease grows process analysis and assistance in surgical applications are some of medical images applications. We need to be able to compare different modalities in medical images such as X-ray, PET, MRI, and CT... , or sometimes doctors need to take images of a patient in a same modality but in different times and directions. In which in order to be able to do theses comparisons we need to first align these images by using image registration methods. Image registration is an image processing method in which tries to find a geometrical transformation that would map different...
Automatic localization of cephalometric landmarks
, Article ISSPIT 2007 - 2007 IEEE International Symposium on Signal Processing and Information Technology, Cairo, 15 December 2007 through 18 December 2007 ; 2007 , Pages 396-401 ; 9781424418350 (ISBN) ; Kasaei, S ; Sharif University of Technology
2007
Abstract
Cephalometric analysis has an important role in diagnosis and treatment of dental disharmonies. In this paper, we propose an efficient, fast, and automatic method to localize cephalometric landmarks on digitized x-ray images. The proposed algorithm uses the information of the marked landmarks on a reference normal cephalometry image as the prior knowledge. In the first step of the proposed method, the image is automatically divided into several regions and three main control points are located on it. These are then matched to their corresponding points on the reference image to form an affine transform matrix that describes how other points on the reference image should be mapped to the...
Spatiotemporal registration and fusion of transthoracic echocardiography and volumetric coronary artery tree
, Article International Journal of Computer Assisted Radiology and Surgery ; Volume 16, Issue 9 , 2021 , Pages 1493-1505 ; 18616410 (ISSN) ; Behnam, H ; Fatemizadeh, E ; Faghihi Langroudi, T ; Bayat, F ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
Purpose: Cardiac multimodal image fusion can offer an image with various types of information in a single image. Many coronary stenosis, which are anatomically clear, are not functionally significant. The treatment of such kind of stenosis can cause irreversible effects on the patient. Thus, choosing the best treatment planning depend on anatomical and functional information is very beneficial. Methods: An algorithm for the fusion of coronary computed tomography angiography (CCTA) as an anatomical and transthoracic echocardiography (TTE) as a functional modality is presented. CCTA and TTE are temporally registered using manifold learning. A pattern search optimization algorithm, using...