An Atmospheric Visibility Grading Method Based on Ensemble Learning and Stochastic Weight Average

Abstract

In order to adequately characterize the visual characteristics of atmospheric visibility and overcome the disadvantages of the traditional atmospheric visibility measurement method with significant dependence on preset reference objects, high cost, and complicated steps, this paper proposed an ensemble learning method for atmospheric visibility grading based on deep neural network and stochastic weight averaging. An experiment was conducted using the scene of an expressway, and three visibility levels were set, i.e., Level 1, Level 2, and Level 3. Firstly, the EfficientNet was transferred to extract the abstract features of the images. Then, training and grading were performed on the feature sets through the SoftMax regression model. Subsequently, the feature sets were ensembled using the method of stochastic weight averaging to obtain the atmospheric visibility grading model. The obtained datasets were input into the grading model and tested. The grading model classified the results into three categories, with the grading accuracy being 95.00%, 89.45%, and 90.91%, respectively, and the average accuracy of 91.79%. The results obtained by the proposed method were compared with those obtained by the existing methods, and the proposed method showed better performance than those of other methods. This method can be used to classify the atmospheric visibility of traffic and reduce the incidence of traffic accidents caused by atmospheric visibility.

Visibility Estimation Based on Weakly Supervised Learning under Discrete Label Distribution

“…Based on the distinct loss functions in the two branches, the overall loss function of this method is defined by Loss = Loss CE + λ * Loss KL (14) where λ denotes a hyper parameter to balance Loss CE and Loss KL .…”

“…The image classification networks that have been proposed so far include AlexNet [7], ResNet [8], VGG [9], Inception [10][11][12], and so on. Shengyan Li et al [13] and Xiuguo Zou et al [14] directly used these classification networks for visibility estimation.…”