Title:Underwater Optical Image Coding for Marine Health Monitoring Based on DCT
VOLUME: 15
Author(s):Mohammad Kazem Moghimi and Farahnaz Mohanna*
Affiliation:Department of Communication Engineering, University of Sistan and Baluchestan, Zahedan, Department of Communication Engineering, University of Sistan and Baluchestan, Zahedan
Keywords:Marine health, underwater optical imaging, image compression, discrete cosine transform.
Abstract:Background: Optical imaging in the underwater environment to monitor marine objects
is now a hot topic of research which can be used for environmental healthcare systems
through the underwater ecosystem. Among different areas of research, image coding techniques
are widely applied to compress data for reliable communications. One of the challenges faced during
the underwater communications is having a low bit rate in acoustic links, particularly while
doing imaging in deep waters (in this condition, light needed for imaging is provided by a power
supply).
Methods: Two Dimensional-Discrete Cosine Transform (2D-DCT) is the main technique that we
want to use for image compression, to test two different patch sizes in 2D-DCT to study the patch
size effect on the quality of compression, execution time and preservation ability of highfrequency
information in edges.
Results: The results clearly show that a larger patch size can always be better in terms of computational
complexity, quality of coded images and also edge preservation when we use DCT for the
compression process.
Discussion: Although this research approves the approach of JPEG codec once again for using the
largest sub-image block in image compression (in terms of similarity and complexity), however,
the use of an edge preservation factor is a new finding for our research. On the other hand, using
the largest patch size is not a general approach for all image processing applications, because
some studies have shown that smaller patch may be more effective for some other applications.
