Alfred J. Mwambela

Work place: University of Dar es Salaam, Department of Electronics and Telecommunications Engineering P.O. Box 33335, Dar es Salaam, Tanzania



Research Interests: Computer systems and computational processes, Information Systems


Alfred Mwambela received his B.Sc. degree in Applied Physics in 1988 from the University of Dar-es-Salaam, Tanzania, his M.Sc. degree in Electronics in 1993 from Durham University, UK and a PhD degree in Industrial process tomography in 1999 from the University of Dar-es-Salaam. Currently, he is working in the Department of Electronics and Telecommunications Engineering of the University of Dar-es-Salaam. His research interest has been in the areas of non-invasive digital imaging systems, telecommunication technologies, computing services development and e-learning.

Author Articles
Comparative Performance Evaluation of Entropic Thresholding Algorithms Based on Shannon, Renyi and Tsallis Entropy Definitions for Electrical Capacitance Tomography Measurement Systems

By Alfred J. Mwambela

DOI:, Pub. Date: 8 Apr. 2018

The concept of entropy as a measure of information has been extensively applied in information theory and related fields. The complex nature of information has resulted in some proposed entropy definitions. In image processing, the entropy concept has been used in developing thresholding techniques based on maximum entropy principles for image segmentation, enhancement and object detection purposes. In this article, entropy definitions are analysed to establish their relationship and after that evaluate their performance in image thresholding. Static simulated data from Electrical Capacitance Tomography measurement system for annular and stratified flows in multiphase hydrocarbons production has been used. Performance evaluation results of thresholding algorithms using Renyi entropy has shown to improve the measurements, particularly for stratified flow regimes. The improvement is solely based on the entropy definition, and it has been observed the introduced controlling parameters do not affect its performance. Renyi entropic thresholding algorithm is relatively robust as it is independent of the controlling parameter q and the grey level resolution. Therefore, there is the potential possibility of using Renyi entropic thresholding to improve measurements in hydrocarbons flow measurement using Electrical Capacitance Tomography measurement system.

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