Liu Huaqian, Zheng Xiujuan, Wang Yan, Zhang Yun, Liu Kai
School of Electrical Engineering, Sichuan University, Chengdu 610065, P.R.China.
School of Electronics and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, P.R.China.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2021 Jun 25;38(3):512-519. doi: 10.7507/1001-5515.202008022.
Vision is an important way for human beings to interact with the outside world and obtain information. In order to research human visual behavior under different conditions, this paper uses a Gaussian mixture-hidden Markov model (GMM-HMM) to model the scanpath, and proposes a new model optimization method, time-shifting segmentation (TSS). The TSS method can highlight the characteristics of the time dimension in the scanpath, improve the pattern recognition results, and enhance the stability of the model. In this paper, a linear discriminant analysis (LDA) method is used for multi-dimensional feature pattern recognition to evaluates the rationality and the accuracy of the proposed model. Four sets of comparative trials were carried out for the model evaluation. The first group applied the GMM-HMM to model the scanpath, and the average accuracy of the classification could reach 0.507, which is greater than the opportunity probability of three classification (0.333). The second set of trial applied TSS method, and the mean accuracy of classification was raised to 0.610. The third group combined GMM-HMM with TSS method, and the mean accuracy of classification reached 0.602, which was more stable than the second model. Finally, comparing the model analysis results with the saccade amplitude (SA) characteristics analysis results, the modeling analysis method is much better than the basic information analysis method. Via analyzing the characteristics of three types of tasks, the results show that the free viewing task have higher specificity value and a higher sensitivity to the cued object search task. In summary, the application of GMM-HMM model has a good performance in scanpath pattern recognition, and the introduction of TSS method can enhance the difference of scanpath characteristics. Especially for the recognition of the scanpath of search-type tasks, the model has better advantages. And it also provides a new solution for a single state eye movement sequence.
视觉是人类与外界互动并获取信息的重要方式。为了研究不同条件下的人类视觉行为,本文采用高斯混合隐马尔可夫模型(GMM-HMM)对扫描路径进行建模,并提出了一种新的模型优化方法——时移分割(TSS)。TSS方法能够突出扫描路径中时间维度的特征,提高模式识别结果,并增强模型的稳定性。本文采用线性判别分析(LDA)方法进行多维度特征模式识别,以评估所提模型的合理性和准确性。对该模型进行了四组对比试验。第一组应用GMM-HMM对扫描路径进行建模,分类平均准确率可达0.507,大于三分类的机会概率(0.333)。第二组试验应用TSS方法,分类平均准确率提高到0.610。第三组将GMM-HMM与TSS方法相结合,分类平均准确率达到0.602,比第二个模型更稳定。最后,将模型分析结果与扫视幅度(SA)特征分析结果进行比较,建模分析方法比基本信息分析方法要好得多。通过分析三种类型任务的特征,结果表明自由观看任务具有更高的特异性值,并且对提示目标搜索任务具有更高的敏感性。综上所述,GMM-HMM模型在扫描路径模式识别中具有良好的性能,TSS方法的引入可以增强扫描路径特征的差异。特别是对于搜索型任务的扫描路径识别,该模型具有更好的优势。并且它也为单状态眼动序列提供了一种新的解决方案。