基于卷积神经网络的交通标志模糊影像识别

当前方法不能有效的识别交通标志模糊影像,且识别交通标志所用的时间较长,存在识别效果差和识别效率低的问题。提出基于卷积神经网络的交通标志模糊影像识别方法,首先对交通标志模糊图像做亮度均衡化处理,消除交通标志自身因素和天气因素对交通标志识别过程产生的影响。对均衡化处理后的图像进行分割,计算各个图像块的显著度,挑选显著度最高的图像块作为交通标志图像的感兴趣区域。提取感兴区域中存在的HOG特征向量和LBP特征向量,对HOG特征向量和LBP特征向量进行融合,得到交通标志图像的HOG-LBP特征。将HOG-LBP特征输入卷积神经网络中,在卷积神经网络中进行前向计算和反向计算,根据计算结果调整偏差和权值,输出交通标志模糊影像的识别结果,实现交通标志模糊影像的识别。仿真结果表明,所提方法的识别效果好、识别效率高。     

基于外观特征与神经网络的交通标志识别

不同种类的交通标志具有特定的颜色及形状等外观特征,本文利用此特点设计了一个自动交通标志识别系统。该系统首先应用HIS彩色模型及标志的形状特征确定彩色图像中的标志区域及标志所属的种类。系统再应用自组织神经网络（S0MNN）进一步识别标志模式。实验证明了该方法的有效性与鲁棒性。     

一种新的退化交通标志图像的分类算法研究

为了识别退化的交通标志图像,提出了一种新的分类算法。该算法在处理图像的退化问题时,采用模糊—仿射不变距直接提取图像的特征而不需要图像的清晰化处理;在利用模糊—仿射不变距提取图像特征的基础上,采用递归正交最小二乘算法设计了一种新的径向基概率神经网络分类器。仿真结果表明:模糊—仿射不变距是一种有效的处理退化的交通标志图像的方法,所设计的径向基概率神经网络分类器不仅具有精简的结构,而且,具有较好分类和推广性能。     

基于高稳定SURF特征的交通标志识别

针对光照变化和部分遮挡这两种情形,提出一种基于多帧视频图像的高稳定特征的交通标志识别方法。利用有交通标志的多帧视频图像的SURF特征建立bag of SURFs特征向量集,与标准交通标志图像的模板特征向量集匹配,采用权值计分策略的最高得分确定交通标志的识别结果。对三种情形下的公开视频图像集进行了实验并与最新方法进行对比分析,结果表明新方法的交通标志识别效果具有明显的优越性,是在光照变化和部分遮挡情形下一种有效的交通标志识别方法。     

基于多尺度特征提取与特征融合的交通标志检测

基于卷积神经网络的交通标志检测算法在对现实中复杂的交通场景图像进行交通标志检测时,难以同时解决定位和分类两项任务,并且目标检测领域相关算法所使用的公开数据集提供的图像和交通标志的种类不能满足现实交通场景中复杂的情况。建立一个新的道路交通标志数据集,在YOLOv4算法的基础上针对现实交通场景图像的复杂性和图像中交通标志尺寸差异较大的特点,设计多尺寸特征提取模块和增强特征融合模块,提高算法同时定位和分类交通标志的能力。在此基础上,对算法中不同的模块设置不同的参数进行对照实验,得到一组表现最优的参数,用于检测现实交通场景图片中的交通标志。在道路交通标志数据集上的实验结果表明,该算法相比基于卷积神经网络的同类型任务目标检测算法具有更高的检测精度,平均精度均值达到83.63%。     

基于android系统的图像内容检测

本文提出一中基于android系统的人脸检测方法,可以针对不同分辨率下的多个人脸进行检测,并针对多检测目标环境提出了修正算法,结果证明能提高多人脸检测条件下的识别正确率。利用SQLite创建基于图像内容的特征数据库,以特征检索的方式对图像进行分类。同时介绍了基于Windows系统的Android开发环境搭建和算法实现的关键步骤。     

Understanding gestures with systematic variations in movement dynamics

Sign language communication includes not only lexical sign gestures but also grammatical processes which represent inflections through systematic variations in sign appearance. We present a new approach to analyse these inflections by modelling the systematic variations as parallel channels of information with independent feature sets. A Bayesian network framework is used to combine the channel outputs and infer both the basic lexical meaning and inflection categories. Experiments using a simulated vocabulary of six basic signs and five different inflections (a total of 20 distinct gestures) obtained from multiple test subjects yielded 85.0% recognition accuracy. We also propose an adaptation scheme to extend a trained system to recognize gestures from a new person by using only a small set of data from the new person. This scheme yielded 88.5% recognition accuracy for the new person while the unadapted system yielded only 52.6% accuracy.     

Exploiting street-level panoramic images for large-scale automated surveying of traffic signs

Accurate and up-to-date inventories of traffic signs contribute to efficient road maintenance and a high road safety. This paper describes a system for the automated surveying of road signs from street-level images. This is an extremely challenging task, as the involved capturings are non-densely sampled, captured under a wide range of weather conditions and signs may be distorted. The described system is designed in a generic and learning-based fashion, which enables the recognition of different sign appearance classes with the same algorithms, based on class-specific training data. The system starts with detection of the signs visible within each image, using a detection cascade. Next, the 3D position of the signs that are detected consequently within consecutive capturings is calculated. Afterwards, each positioned road sign is classified to retrieve its sign type, thereby exploiting all detections used during positioning of the respective sign. The presented system is intended for large-scale application and currently supports 11 sign appearance classes, containing 176 different sign types. Performance evaluations conducted on a large, real-world dataset (68,010 images) show that our approach accurately positions 95.5 % of the 3,385 present signs, where 96.3 % of them are also correctly classified. Furthermore, our system localized 98.5 % of the signs in at least a single image. Our system design allows for appending a limited manual correction stage to attain a very high performance, so that sign inventories can be created cost effectively.     

基于颜色手套的中国手指语字母的动静态识别

作为一种高度结构化的语言,手语具有与口语和文字语言一样的表达能力。基于视觉的手语识别不仅更加符合人们的习惯而且具有非常广阔的应用空间。该文采用指尖染色和手指染色的颜色手套模型实现了可以识别中国手指字母表30个基本手形的动静态手势识别系统,识别率达到100%。     

Recognizing plankton images from the shadow image particle profiling evaluation recorder

We present a system to recognize underwater plankton images from the shadow image particle profiling evaluation recorder (SIPPER). The challenge of the SIPPER image set is that many images do not have clear contours. To address that, shape features that do not heavily depend on contour information were developed. A soft margin support vector machine (SVM) was used as the classifier. We developed a way to assign probability after multiclass SVM classification. Our approach achieved approximately 90% accuracy on a collection of plankton images. On another larger image set containing manually unidentifiable particles, it also provided 75.6% overall accuracy. The proposed approach was statistically significantly more accurate on the two data sets than a C4.5 decision tree and a cascade correlation neural network. The single SVM significantly outperformed ensembles of decision trees created by bagging and random forests on the smaller data set and was slightly better on the other data set. The 15-feature subset produced by our feature selection approach provided slightly better accuracy than using all 29 features. Our probability model gave us a reasonable rejection curve on the larger data set.     

Detection and classification of road signs in natural environments

An automatic road sign recognition system first locates road signs within images captured by an imaging sensor on-board of a vehicle, and then identifies the detected road signs. This paper presents an automatic neural-network-based road sign recognition system. First, a study of the existing road sign recognition research is presented. In this study, the issues associated with automatic road sign recognition are described, the existing methods developed to tackle the road sign recognition problem are reviewed, and a comparison of the features of these methods is given. Second, the developed road sign recognition system is described. The system is capable of analysing live colour road scene images, detecting multiple road signs within each image, and classifying the type of road signs detected. The system consists of two modules: detection and classification. The detection module segments the input image in the hue-saturation-intensity colour space, and then detects road signs using a Multi-layer Perceptron neural-network. The classification module determines the type of detected road signs using a series of one to one architectural Multi-layer Perceptron neural networks. Two sets of classifiers are trained using the Resillient-Backpropagation and Scaled-Conjugate-Gradient algorithms. The two modules of the system are evaluated individually first. Then the system is tested as a whole. The experimental results demonstrate that the system is capable of achieving an average recognition hit-rate of 95.96% using the scaled-conjugate-gradient trained classifiers.     

Translation invariants of Zernike moments

Moment functions defined using a polar coordinate representation of the image space, such as radial moments and Zernike moments, are used in several recognition tasks requiring rotation invariance. However, this coordinate representation does not easily yield translation invariant functions, which are also widely sought after in pattern recognition applications. This paper presents a mathematical framework for the derivation of translation invariants of radial moments defined in polar form. Using a direct application of this framework, translation invariant functions of Zernike moments are derived algebraically from the corresponding central moments. Both derived functions are developed for non-symmetrical as well as symmetrical images. They mitigate the zero-value obtained for odd-order moments of the symmetrical images. Vision applications generally resort to image normalization to achieve translation invariance. The proposed method eliminates this requirement by providing a translation invariance property in a Zernike feature set. The performance of the derived invariant sets is experimentally confirmed using a set of binary Latin and English characters.     

JPEG compressed image retrieval via statistical features

To improve efficiency of compressed image retrieval, we propose a novel statistical feature extraction algorithm in this paper to characterize the image content directly in its compressed domain. The statistical feature extracted is mainly through computing a set of moments directly from DCT coefficients without involving full decompression or inverse DCT. Following the algorithm design, a content-based image retrieval system is implemented especially targeting retrieving joint picture expert group compressed images. Theoretical analysis and experimental results support that the system is robust to translation, rotation and scale transform with minor disturbance, and the system achieves good performances in terms of retrieval efficiency and effectiveness.     

基于几何特征的静态字母手势识别算法

针对聋哑人哑语手势自动识别问题的复杂性,研究了手势几何特征的多样性及提取和识别方法,提出了一种基于几何特征的手势识别算法.首先,对手势图像进行肤色分割、边缘检测以及逻辑运算,然后,计算其质心面积等多项几何特征,通过实验方法测定最佳特征权值,最后,将其与样本图像特征值进行匹配,最佳匹配即为检测结果.根据30个字母手势创建了3套手势库,其中1套作为样本集,2套作为测试集.实验结果表明,通过该方法进行特征提取来识别汉语字母手势,可有效提高识别率,测试集识别率达到93.33％.     

Embedded real-time speed limit sign recognition using image processing and machine learning techniques

The number of traffic accidents in Brazil has reached alarming levels and is currently one of the leading causes of death in the country. With the number of vehicles on the roads increasing rapidly, these problems will tend to worsen. Consequently, huge investments in resources to increase road safety will be required. The vertical R-19 system for optical character recognition of regulatory traffic signs (maximum speed limits) according to Brazilian Standards developed in this work uses a camera positioned at the front of the vehicle, facing forward. This is so that images of traffic signs can be captured, enabling the use of image processing and analysis techniques for sign detection. This paper proposes the detection and recognition of speed limit signs based on a cascade of boosted classifiers working with haar-like features. The recognition of the sign detected is achieved based on the optimum-path forest classifier (OPF), support vector machines (SVM), multilayer perceptron, k-nearest neighbor (kNN), extreme learning machine, least mean squares, and least squares machine learning techniques. The SVM, OPF and kNN classifiers had average accuracies higher than 99.5 %; the OPF classifier with a linear kernel took an average time of 87 \(\upmu\)s to recognize a sign, while kNN took 11,721 \(\upmu\)s and SVM 12,595 \(\upmu\)s. This sign detection approach found and recognized successfully 11,320 road signs from a set of 12,520 images, leading to an overall accuracy of 90.41 %. Analyzing the system globally recognition accuracy was 89.19 %, as 11,167 road signs from a database with 12,520 signs were correctly recognized. The processing speed of the embedded system varied between 20 and 30 frames per second. Therefore, based on these results, the proposed system can be considered a promising tool with high commercial potential.

     

利用小波和矩进行基于形状的图象检索

形状是图象中目标的重要特征,基于形状的图象检索近来在基于内容的图象库系统和管理和应用中得到越来越多的重视。现已研制的系统存在两个问题。一是性能的不稳定性;二是相对平移,旋转和尺度变换的变化性,针对上问题,该文提出了一种新的基于形状的图象检索算法。此算法先对亮度图象图象进行小波模极大值变换以得到多尺度的边界图象,再利用７个不变矩提取每一尺度边界图象的特征,所有尺度上的矩共同组成图象的特征向量。图象的     

Medical Sign Recognition of Lung Nodules Based on Image Retrieval with Semantic Features and Supervised Hashing

Sign recognition is important for identifying benign and malignant nodules. This paper proposes a new sign recognition method based on image retrieval for lung nodules. First, we construct a deep learning framework to extract semantic features that can effectively represent sign information. Second, we translate the high-dimensional image features into compact binary codes with principal component analysis (PCA) and supervised hashing. Third, we retrieve similar lung nodule images with the presented adaptive-weighted similarity calculation method. Finally, we recognize nodule signs from the retrieval results, which can also provide decision support for diagnosis of lung lesions. The proposed method is validated on the publicly available databases: lung image database consortium and image database resource initiative (LIDC-IDRI) and lung computed tomography (CT) imaging signs (LISS). The experimental results demonstrate our retrieval method substantially improves retrieval performance compared with those using traditional Hamming distance, and the retrieval precision can achieve 87.29% when the length of hash code is 48 bits. The entire recognition rate on the basis of the retrieval results can achieve 93.52%. Moreover, our method is also effective for real-life diagnosis data.