Removing backscatter to enhance the visibility of underwater objects

Underwater vision enhancement is a vital issue in ocean engineering and backscatter removing is widely used in the restoration procedure. With the development of ocean engineering and the increasing of ocean exploration, image and video are essential means to obtain and record information. However,...

Full description

Bibliographic Details
Main Author: Tang, Xiaoyu
Other Authors: Chau Lap Pui
Format: Thesis
Language:English
Published: 2017
Subjects:
Online Access:http://hdl.handle.net/10356/72553
_version_ 1826127956224770048
author Tang, Xiaoyu
author2 Chau Lap Pui
author_facet Chau Lap Pui
Tang, Xiaoyu
author_sort Tang, Xiaoyu
collection NTU
description Underwater vision enhancement is a vital issue in ocean engineering and backscatter removing is widely used in the restoration procedure. With the development of ocean engineering and the increasing of ocean exploration, image and video are essential means to obtain and record information. However, underwater images and videos always suffer from low contrast and color distortion due to the existence of dust-like particles and light attenuation. As a result, method to restore underwater videos and images has been drawn more and more attention. In this dissertation, the physical process of underwater light propagation is analyzed. The proposed method is based on optical haze model and fusion of adjacent frames. The procedure mainly includes: background light estimation, block-based transmission estimation and refinement; background light fusion between sequential frames and transmission fusion among adjacent frames; haze removal based on haze model; color correction by stretching pixel values. Both subjective and objective measurements are adopted to evaluate and compare the results of the proposed method and other state-of-the-art methods. The results of the proposed method show that it could enhance the visibility and fidelity of underwater scenes in videos, especially in open scenes with dense haze in deep sea environment. Also, the proposed method could achieve great clearness in underwater scenes while keeping the contrast and resolution at a proper level.
first_indexed 2024-10-01T07:17:00Z
format Thesis
id ntu-10356/72553
institution Nanyang Technological University
language English
last_indexed 2024-10-01T07:17:00Z
publishDate 2017
record_format dspace
spelling ntu-10356/725532023-07-04T15:48:25Z Removing backscatter to enhance the visibility of underwater objects Tang, Xiaoyu Chau Lap Pui School of Electrical and Electronic Engineering DRNTU::Engineering::Electrical and electronic engineering Underwater vision enhancement is a vital issue in ocean engineering and backscatter removing is widely used in the restoration procedure. With the development of ocean engineering and the increasing of ocean exploration, image and video are essential means to obtain and record information. However, underwater images and videos always suffer from low contrast and color distortion due to the existence of dust-like particles and light attenuation. As a result, method to restore underwater videos and images has been drawn more and more attention. In this dissertation, the physical process of underwater light propagation is analyzed. The proposed method is based on optical haze model and fusion of adjacent frames. The procedure mainly includes: background light estimation, block-based transmission estimation and refinement; background light fusion between sequential frames and transmission fusion among adjacent frames; haze removal based on haze model; color correction by stretching pixel values. Both subjective and objective measurements are adopted to evaluate and compare the results of the proposed method and other state-of-the-art methods. The results of the proposed method show that it could enhance the visibility and fidelity of underwater scenes in videos, especially in open scenes with dense haze in deep sea environment. Also, the proposed method could achieve great clearness in underwater scenes while keeping the contrast and resolution at a proper level. Master of Science (Communications Engineering) 2017-08-28T11:36:22Z 2017-08-28T11:36:22Z 2017 Thesis http://hdl.handle.net/10356/72553 en 61 p. application/pdf
spellingShingle DRNTU::Engineering::Electrical and electronic engineering
Tang, Xiaoyu
Removing backscatter to enhance the visibility of underwater objects
title Removing backscatter to enhance the visibility of underwater objects
title_full Removing backscatter to enhance the visibility of underwater objects
title_fullStr Removing backscatter to enhance the visibility of underwater objects
title_full_unstemmed Removing backscatter to enhance the visibility of underwater objects
title_short Removing backscatter to enhance the visibility of underwater objects
title_sort removing backscatter to enhance the visibility of underwater objects
topic DRNTU::Engineering::Electrical and electronic engineering
url http://hdl.handle.net/10356/72553
work_keys_str_mv AT tangxiaoyu removingbackscattertoenhancethevisibilityofunderwaterobjects