基于视频分析的飞机机号识别研究

为精确获取飞机机号以便实时掌握飞机起飞与降落时间,文章提出一种改善飞机机号识别的图像增强算法。考虑到机场应用场景对飞机机号的识别影响,本文首先给出相应的数学模型,并设计图像处理算法进行直方图均衡化,噪声消除,阈值分割等处理;通过分类器的迭代训练,实现对飞机机号的字符进行精准识别。文章根据图像算法进行了实验验证,并对验证结果进行了简要分析。

复杂维修场景下飞机机号的定位识别方法

针对在复杂维修场景下飞机数量较多且体积庞大,无法实现准确高效的识别跟踪目标飞机的问题,提出基于YOLOv4目标检测的飞机机号识别算法,该方法首先利用YOLOv4检测算法获得飞机机型和预测框图像信息,然后通过图像处理算法实现飞机骨架细化,并依据机型获取飞机机号位置信息,最后利用OCR(optical character recognition)识别出目标飞机机号信息。实验结果证明,该算法实现了对飞机机号的识别,准确率为75%,帧率为30帧,可达到实时性的目的。

Detection and Classification on Amateur Drones Based on Cepstrum of Radio Frequency Signal

As a prospective component of the future air transportation system,unmanned aerial vehicles(UAVs)have attracted enormous interest in both academia and industry.However,small UAVs are barely supervised in the current situation.Crash accidents or illegal airspace invading caused by these small drones affect public security negatively.To solve this security problem,we use the back-propagation neural network(BPNN),the support-vector machine(SVM),and the k-nearest neighbors(KNN)method to detect and classify the non-cooperative drones at the edge of the flight restriction zone based on the cepstrum of the radio frequency(RF)signal of the drone’s downlink.The signal from five various amateur drones and ambient wireless devices are sampled in an electromagnetic clean environment.The detection and classification algorithm based on the cepstrum properties is conducted.Results of the outdoor experiments suggest the proposed workflow and methods are sufficient to detect non-cooperative drones with an average accuracy of around 90%.The mainstream downlink protocols of amateur drones can be classified effectively as well.

Study of engine noise based on independent component analysis

Independent component analysis was applied to analyze the acoustic signals from diesel engine. First the basic prin-ciple of independent component analysis (ICA) was reviewed. Diesel engine acoustic signal was decomposed into several inde-pendent components (ICs); Fourier transform and continuous wavelet transform (CWT) were applied to analyze the independent components. Different noise sources of the diesel engine were separated, based on the characteristics of different component in time-frequency domain.

A ROBUST EYE LOCALIZATION ALGORITHM FOR FACE RECOGNITION

The accuracy of face alignment affects greatly the performance of a face recognition system. Since the face alignment is usually conducted using eye positions, the algorithm for accurate eye lo- calization is essential for the accurate face recognition. In this paper, an algorithm is proposed for eye localization. First, the proper AdaBoost detection is adaptively trained to segment the region based on the special gray distribution in the region. After that, a fast radial symmetry operator is used to pre- cisely locate the center of eyes. Experimental results show that the method can accurately locate the eyes, and it is robust to the variations of face poses, illuminations, expressions, and accessories.

Unsupervised Color-texture Image Segmentation

The measure J in J value segmentation (JSEG) fails to represent the discontinuity of color, which degrades the robustness and discrimination of JSEG. An improved approach for JSEG algorithm was proposed for unsupervised color-texture image segmentation. The texture and photometric invariant edge information were combined, which results in a discriminative measure for color-texture homogeneity. Based on the image whose pixel values are values of the new measure, region growing-merging algorithm used in JSEG was then employed to segment the image. Finally, experiments on a variety of real color images demonstrate performance improvement due to the proposed method.