Edge Detection Algorithm For Enhancement of Linear Back Projection Tomographic Images

2014 ◽  
Vol 69 (8) ◽  
Author(s):  
Jaysuman Pusppanathan ◽  
Mahdi Faramarzi ◽  
Fazlul Rahman Yunus ◽  
Nor Muzakkir Nor Ayob ◽  
Ruzairi Abdul Rahim ◽  
...  

Process tomography (PT) is a leading technique for multiphase flow measurement and flow monitoring systems in various fields. PT has the advantage of interpreting acquired measurement data and transforming it into visual tomographic images. The most common method of image reconstruction uses the linear back projection algorithm which often results in blurry images. This paper proposes an enhancement of the reconstructed images using an edge detection image processing technique to convolve with the original image. This filtering technique calculates approximation changes of the horizontal and vertical image derivatives, thus further enhancing image accuracy. Several ultrasonic tomography images were put into a simulation test to validate it. Hence, the image results are being assessed for its performance.

2014 ◽  
Vol 70 (3) ◽  
Author(s):  
Mohd Hafiz Fazalul Rahiman ◽  
Ruzairi Abdul Rahim ◽  
Herlina Abdul Rahim ◽  
Zulkarnay Zakaria ◽  
Muhammad Jaysuman Pusppanathan

This paper studies the solution for inverse and forward problems for an ultrasonic tomography. Transmission-mode approach has been used for sensing the liquid/gas two-phase flow, which is a kind of strongly inhomogeneous medium. The imaging technique for two-phase flow using fan-shaped beam scanning geometry was presented. In this work, the tomographic images are derived from Back-Projection Algorithm. Some of the results based on the Linear Back-Projection algorithm (LBP) and the Hybrid Reconstruction algorithm (HR) was also presented.


Author(s):  
Mohd Hafiz Fazalul Rahiman ◽  
Ruzairi Abdul Rahim ◽  
Herlina Abdul Rahim

Kertas ini membincangkan algoritma pembangunan imej bagi kegunaan dalam tomografi ultrasonik. Terdapat tiga jenis algoritma pembangunan iaitu Linear Back Projection, Hybrid Reconstruction dan Hybrid Binary Reconstruction. Algoritma tersebut telah diuji ke atas sistem tomografi ultrasonik berdasarkan kepada beberapa bayang yang telah dikenalpasti dan objek–objek sebenar. Prestasi algoritma tersebut telah di analisa dan bincangkan pada bahagian akhir kertas ini. Kata kunci: Algoritma pembangunan; tomografi ultrasonic; pemprosesan image; mabuk This paper presented image reconstruction algorithms for use in ultrasonic tomography. There are three types of reconstruction algorithms namely Linear Back Projection, Hybrid Reconstruction and Hybrid Binary Reconstruction. The algorithms have been evaluated on ultrasonic tomography system based on several known phantoms and real objects. The performance of the algorithms have been analysed and discussed at the end of the paper. Key words: Reconstruction algorithm; ultrasonic tomography; image processing


2014 ◽  
Vol 69 (8) ◽  
Author(s):  
Zulkarnay Zakaria ◽  
Ibrahim Balkhis ◽  
Lee Pick Yern ◽  
Nor Muzakkir Nor Ayob ◽  
Mohd Hafiz Fazalul Rahiman ◽  
...  

Magnetic induction tomography is a new non-invasive technology, based on eddy current discovery of electromagnetic induction by Michael Faraday. Through this technique, the passive electrical properties distribution of an object can be obtained by the use of image reconstruction algorithm implemented in this system. There are many types of image reconstruction that have been developed for this modality, however in this paper only two algorithms discussed, Linear Back Projection and Eminent Pixel Reconstruction. Linear Back Projection algorithm is the most basic type of image reconstruction. It is the simplest and fast algorithm out of all types of algorithms, whereas Eminent Pixel Reconstruction algorithm is an improved algorithm which provided better images and has been implemented in other modalities such as optical tomography. This paper has implemented Eminent Pixel Reconstruction in magnetic induction tomography applications and the performance is compared to Linear Back Projection based on the simulation of the fourteen types of simulated phantoms of homogenous and isotropic conductivity property. It was found that Eminent Pixel Reconstruction has produced better images relative to Linear Back Projection, however the images are still poor when the objects are located near to the excitation coil or sensor and it is worse when the distance between objects are near to each other.


2015 ◽  
Vol 73 (6) ◽  
Author(s):  
Nur Adila Mohd Razali ◽  
Aizat Azmi ◽  
Shahrulnizahani Mohammad Din ◽  
Pei Song Chee ◽  
Nor Muzakkir Nor Ayob ◽  
...  

Miniaturized device offers portability, high throughput and faster time response compared to macroscale devices. In microdevices, most of the application utilizes planar electrode for microanalysis process as it is inexpensive, highly controllable system and easy for installation. In addition, miniaturized planar sensor offers great potential for microscale medical diagnosis, chemical analysis, environmental analysis, cell culture application and single cell measurement using tomography measurement. In this project, a miniaturized planar tomography system is developed for multiphase sample detection such as liquid-solid and liquid-liquid. Eight-electrode device was fabricated on the copper plated printed circuit board (PCB) using the commercial fabrication technique. The ability of the proposed device in reconstructing images of a multiphase sample using Linear Back Projection algorithm is tested. Experimental results show that the reconstructed images closely resemble with the cross-section of the stagnant multiphase sample.


Author(s):  
R. Amirulah ◽  
S. Z. M. Muji ◽  
M. H. Jabbar ◽  
Ruzairi Abdul Rahim ◽  
Mohd Hafiz Fazalul Rahiman

Current image processing techniques for drivable road detection make use of lane markings. However, most roads lack lane markings which make such techniques obsolete. For such conditions, an image processing technique is required which identifies the boundaries of the road based on the color differences between the road and the surroundings. This paper proposes a flood fill road detection approach in which we first analyze a sample of the road and compute its RGB pixel distribution. The pixel range is used to detect the other road pixels in the image. Edge detection algorithms are then applied on the detected road to give road edge. It classifies the road on the basis of the visible differences between the road and its neighborhood. It allows for subtle color differences on the road surface, and unlike a color mask, due to the inherent growing nature of a flood fill algorithm, it does not detect neighborhood elements beyond the boundary having features similar to the road. This technique also manages to detect any obstructions on the road as opposed to other edge detection algorithms. We also propose methods to enable quick computation of otherwise expensive flood-fill algorithm. The method was tested on both marked and unmarked lanes and produced satisfying results for both images and videos.


2005 ◽  
Vol 44 (3) ◽  
pp. 265-273
Author(s):  
J. C. Gamio ◽  
C. Ortíz-Alemán ◽  
R. Martin

La Tomografía de Capacitancia Eléctrica (TCE) es una nueva tecnología capaz de lidiar con la complejidad de la medición de flujos bifásicos de gas-aceite, derivando la distribución de componentes en dos planos adyacentes a lo largo de un ducto. Una de sus aplicaciones más prometedoras es la visualización de flujos de gas y aceite. TCE ofrece algunas ventajas sobre otras modalidades tomográficas: no hay radiación, una respuesta rápida, bajo costo, es una técnica no intrusiva y no invasiva, y la posibilidad de operar con altas temperaturas y altas presiones. El método denominado "linear back-projection (LBP)" es una de las técnicas más populares que se emplean en la reconstrucción de imágenes a partir de datos de tomografía de capacitancia eléctrica. A pesar de su pobre exactitud, es un procedimiento simple y rápido capaz de operar en tiempo real en muchas aplicaciones y ha permanecido como una opción muy popular. Sin embargo, desde que fue propuesto por vez primera ha carecido de un suporte formal, en el contexto de esta aplicación. Su única justificación radica en que es una adaptación de un método comúnmente empleado en la tomografía médica de rayos X, así como en el hecho de que produce imágenes útiles (aunque sólo "cualitativamente" buenas). En este trabajo se presenta una forma ilustrativa de interpretar el método LBP. Se muestra cómo el método LBP está basado en la linealización de una forma normalizada del problema directo. Más específicamente, el problema directo normalizado se aproxima mediante una serie de hiperplanos. La matriz de reconstrucción utilizada en el método LBP resulta ser una transpuesta "ponderada" del operador lineal (matriz) que define el problema directo normalizado. Los renglones de esta última matriz contienen la información de los mapas de sensitividades empleados en el método LBP.


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