Improved range estimation and underwater image enhancement under turbidity by opti-acoustic stereo imaging

Mohammadreza Babaee, Shahriar Negahdaripour

Research output: Chapter in Book/Report/Conference proceedingConference contribution

7 Scopus citations


Images recorded in turbid waters suffer from various forms of signal degradation due to light absorption, scattering and backscatter. Much of the earlier work to enhance color, contrast and sharpness follow the single-image dehazing approach from the atmospheric imaging literature. Requiring knowledge of both range to scene objects and ambient lighting, various techniques differ in how they estimate the information from various image regions. Moreover, some assumptions are made that hold for most images recorded in air and clear waters, but are often violated in turbid environments, leading to poor results. Alternatively, stereo imaging and polarization have been explored for simultaneous range estimating and image dehazing, however, these can become ineffective with low visibility and (or) weak polarization cue. This work explores a methodology that utilizes the visual cues in multi-modal optical and sonar images, namely, the occluding contours of various scene objects that can be detected and matched more robustly than point features. Calculating the sparse 3-D positions of these contours from opti-acosutic stereo data, we infer a dense range map by exploiting an MRF-based statistical framework, where image intensities and range values serve as observation and hidden variables. Additionally, the opti-acoustic epipolar geometry guides the inference of the MRF by refining neighborhood pixels. The improved performance over other state-of-the-art techniques is demonstrated using images recorded under different turbidity conditions.

Original languageEnglish (US)
Title of host publicationMTS/IEEE OCEANS 2015 - Genova
Subtitle of host publicationDiscovering Sustainable Ocean Energy for a New World
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)9781479987368
StatePublished - Sep 17 2015
EventMTS/IEEE OCEANS 2015 - Genova - Genova, Italy
Duration: May 18 2015May 21 2015

Publication series

NameMTS/IEEE OCEANS 2015 - Genova: Discovering Sustainable Ocean Energy for a New World


OtherMTS/IEEE OCEANS 2015 - Genova

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Oceanography


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