Title: Enhancement of mammogram images in SMRT domain using nonlinear mapping functions

Authors: V.L. Jaya; R. Gopikakumari

Addresses: Department of Electronics Engineering, Model Engineering College, Thrikkakkara, Ernakulam, Kerala, India ' Division of Electronics Engineering, School of Engineering, Cochin University of Science and Technology, Kochi, Kerala, India

Abstract: The task of medical image enhancement is to accentuate image features that are clinically relevant and difficult to visualise under normal viewing conditions. Enhancement can be accomplished by increasing image contrast. This paper presents a simple contrast enhancement algorithm in the Sequency based Mapped Real Transform (SMRT) domain. Brightness and contrast of the image are modified by varying DC and AC SMRT coefficients separately. DC SMRT coefficient is changed to bring the image mean to the mid histogram range. Nonlinear mapping functions are used to modify AC SMRT coefficients so as to improve the contrast. Enhancement is quantitatively assessed using second derivative like measurement (SDME) and Image Enhancement Metric (IEM).

Keywords: medical images; image enhancement; brightness; image contrast; sequency based mapped real transform; SMRT; nonlinear mapping; mammograms; breast cancer.

DOI: 10.1504/IJBET.2016.077180

International Journal of Biomedical Engineering and Technology, 2016 Vol.21 No.2, pp.145 - 158

Received: 24 Jul 2015
Accepted: 19 Oct 2015
Published online: 22 Jun 2016 *

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