The proposed method is a new approach for enhancing grayscale images, when the images are map to quaternion space, and then, the quaternion based enhancement technique is used. Namely, the quaternion alpha-rooting method to enhance the so generated “quaternion” image. Currently, there are only very limited techniques to convert a grayscale image to color image, and in this article we propose a novel conversion technique which helps in easily converting a grayscale image to a color or quaternion image. In addition to that, we describe the quaternion alpha-rooting method of quaternion image enhancement. Quaternion approach of enhancement allows for processing the multi-signaled image as a single unit. The fast algorithm of quaternion discrete Fourier transforms makes the implementation of the enhancement method practically possible and effective. The results of image enhancement by the proposed method and comparison with the traditional alpha-rooting of grayscale images are described. The metric used to assess the quality of enhancement shows good values for the results of the proposed enhancement. One of the enhancement metrics is the contrast-based metric referred to as the enhancement measure estimation (EME). Other metrics used to assess the quality of the enhanced images are signal-to-noise ratio (SNR), mean-square-root error (MSRE).

Date Published: 13 May 2019
PDF: 8 pages
Proc. SPIE 10993, Mobile Multimedia/Image Processing, Security, and Applications 2019, 109930T (13 May 2019); doi: 10.1117/12.2519664

Published in SPIE Proceedings Vol. 10993:
Mobile Multimedia/Image Processing, Security, and Applications 2019
Sos S. Agaian; Vijayan K. Asari; Stephen P. DelMarco, Editor(s)