Physical-based optimization for non-physical image dehazing methods

Images captured under hazy conditions (e.g. fog, air pollution) usually present faded colors and loss of contrast. To improve their visibility, a process called image dehazing can be applied. Some of the most successful image dehazing algorithms are based on image processing methods but do not follow any physical image formation model, which limits their performance. In this paper, we propose a post-processing technique to alleviate this handicap by enforcing the original method to be consistent with a popular physical model for image formation under haze. Our results improve upon those of the original methods qualitatively and according to several metrics, and they have also been validated via psychophysical experiments. These results are particularly striking in terms of avoiding over-saturation and reducing color artifacts, which are the most common shortcomings faced by image dehazing methods

Removing rain from a single image via Convolutional Neural Network

受恶劣天气的影响，室外视觉系统所获得的图像会劣化。雨是常见的恶劣天气之一，目前国内外关于去雨的问题已有一些解决的方案，但大多关注于视频去雨。由于该类方法是以丰富的时空相关信息为前提，因而并不适用于单幅图像去雨。近年来，单幅图像去雨的研究逐渐受到重视，然而现有方法需要在去雨效果和图像清晰度之间折中且计算效率低下，难以满足实际应用需求。 为此，本文针对单幅图像去雨，基于变分法和卷积神经网络提出三种新的单幅图像去雨算法，主要研究内容及成果如下： 1.提出基于梯度正则化的单幅图像去雨算法。首先设计一个引导平滑滤波器实现初步去雨。该滤波器在保证输出图像与输入图像一致性的前提下，引入梯度正则项，使其根...Affected by the bad weather, the images obtained by outdoor visual systems always degrade. Rain is one of the common bad weather. At home and abroad, there are some solutions about removal of rain, but most of it aims to videos. It can’t apply to single image since no temporal information can be obtained. Recently, the study of rain removal from a single image gradually receive more attention. Ho...学位：工学硕士院系专业：信息科学与技术学院_信号与信息处理学号：2332013115323