一种基于形态学的路径特征提取算法

在对原始路径图像进行最优化阈值分割后,使用数学形态学中的开运算对分割图像进行边缘提取,使用腐蚀膨胀、择多黑色算子等形态学运算进行边缘的细线化处理,从而在多路径环境中有效地提取了路径特征。并与Sobel算子、拉普拉斯算子、Prewitt算子等传统方法进行了比较,验证基于形态学的方法具有很好的抗噪性。     

舰船红外图像边缘检测方法对比研究

为了对海上舰船红外图像进行分割和目标识别,首先具体分析了六种边缘检测算子Roberts算子、Prewitt算子、Sobel算子、Log算子、Kirsch算子、Canny算子的检测原理,给出了各种检测算子的计算模板。然后采用Roberts算子、Prewitt算子、Sobel算子、Log算子、Kirsch算子、Canny算子对舰船红外图像进行处理,分析比较各个检测算法的检测优缺点。最后用Matlab语言编程实现各种检测算法,通过Matlab软件进行仿真实验,用各种检测算法处理舰船红外图像,直观的给出各检测算子的舰船图像处理效果,并对处理结果进行了比较,得出了在噪声干扰下,Canny算子更容易处理舰船红外图像的结论。     

Rule-based soft computing for edge detection

In this paper, we present a robust rule-based edge detection method. Although generalized edge detection approaches are effective for most images they often fail in others. Thus the goal of our method is to provide more reliable edge detection results that are effective in most images. We implement the proposed method as follows: (1) transform RGB images to YCbCr format, (2) apply Sobel mask in four edge directions (horizontal, vertical, diagonal, anti-diagonal), (3) apply a bi-directional mask in four edge directions (horizontal–diagonal, vertical–diagonal, horizontal–anti-diagonal, vertical–anti-diagonal), and (4) detect rule-based edges by calculating membership degrees. Simulation results demonstrate that the proposed method is effective in most given images. We used three benchmarks approaches (Canny edge mask, high-pass filter, and Sobel mask) to compare the subjective performance quality.     

Robust object tracking via multi-scale patch based sparse coding histogram

There are many visual tracking algorithms that are based on sparse representation appearance model. Most of them are modeled by local patches with fixed patch scale, which make trackers less effective when objects undergone appearance changes such as illumination variation, pose change or partial occlusion. To solve the problem, a novel appearance representation model is proposed via multi-scale patch based sparse coding histogram for robust visual tracking. In this paper, the appearance of an object is modeled by different scale patches, which are represented by sparse coding histogram with different scale dictionaries. Then a similarity measure is applied to the calculation of the distance between the sparse coding histograms of target candidate and target template. Finally, the similarity score of the target candidate is passed to a particle filter to estimate the target state sequentially in the tracking process. Additionally, in order to decrease the visual drift caused by partial occlusion, an occlusion handling strategy is adopted, which takes the spatial information of multi-scale patches and occlusion into account. Based on the experimental results on some benchmarks of video sequences, our tracker outperforms state-of-the-art tracking methods.     

结合连续卷积算子的自适应加权目标跟踪算法

目的 在视觉跟踪领域中,特征的高效表达是鲁棒跟踪的关键,观察到在相关滤波跟踪中,不同卷积层表达了目标的不同方面特征,提出了一种结合连续卷积算子的自适应加权目标跟踪算法。方法 针对目标定位不准确的问题,提出连续卷积算子方法,将离散的位置估计转换成连续位置估计,使得位置定位更加准确;利用不同卷积层的特征表达,提高跟踪效果。首先利用深度卷积网络结构提取多层卷积特征,通过计算相关卷积响应大小,决定在下一帧特征融合时各层特征所占的权重,凸显优势特征,然后使用从不同层训练得到的相关滤波器与提取得到的特征进行相关运算,得到最终的响应图,响应图中最大值所在的位置便是目标所在的位置和尺度。结果 与目前较流行的3种目标跟踪算法在目标跟踪基准数据库（OTB-2013）中的50组视频序列进行测试,本文算法平均跟踪成功率达到85.4%。结论 本文算法在光照变化、尺度变化、背景杂波、目标旋转、遮挡和复杂环境下的跟踪具有较高的鲁棒性。     

数字图像边缘检测的Java实现

介绍几种经典的边缘检测算子，并用Java语言实现数字图像的边缘检测。由于JaVa语言在图像处理方面有其自身的优势，因此整个实现过程具有简单、灵活、适应性强的特点。     

Robust feature learning for online discriminative tracking without large-scale pre-training

Owing to the inherent lack of training data in visual tracking, recent work in deep learning-based trackers has focused on learning a generic representation offline from large-scale training data and transferring the pre-trained feature representation to a tracking task. Offline pre-training is time-consuming, and the learned generic representation may be either less discriminative for tracking specific objects or overfitted to typical tracking datasets. In this paper, we propose an online discriminative tracking method based on robust feature learning without large-scale pre-training. Specifically, we first design a PCA filter bank-based convolutional neural network (CNN) architecture to learn robust features online with a few positive and negative samples in the high-dimensional feature space. Then, we use a simple soft-thresholding method to produce sparse features that are more robust to target appearance variations. Moreover, we increase the reliability of our tracker using edge information generated from edge box proposals during the process of visual tracking. Finally, effective visual tracking results are achieved by systematically combining the tracking information and edge box-based scores in a particle filtering framework. Extensive results on the widely used online tracking benchmark (OTB-50) with 50 videos validate the robustness and effectiveness of the proposed tracker without large-scale pre-training.     

A novel edge detection method with application to the fat content prediction in marbled meat

Intramuscular fat is an important quality criterion, notably juiciness, in meat grading. But traditional visual inspectors are time consuming and destructive. However, edge detection techniques characterize meat surface in consistence, rapid, and non-destructive approach. In this paper, novel edge detection method applied on intramuscular fat is presented based on the energy and skewness as two smoothed versions of the image. Parametric analyses were investigated and the method was tested on several images, producing minimum improvements of 6.451%, 1.667% and 7.826% in signal to noise ratio, mean square error and edges localization, respectively, in comparison to Roberts, Prewitt, Sobel, and Canny detectors.     

边缘检测算子研究及其在医学图像中的应用

阐述了边缘检测在医学图像处理中的重要作用,分析了几种常用算子(Roberts,Sobel,Prewitt,Laplacian,Canny)基本原理及算法实现,并对比各算子的优缺点,并用VC .NET工具编程实现出以上各种算子对一幅人体头部的MRI图进行边缘提取。对实验结果进行分析得出结论,各种不同的算子对同一幅图片进行边缘提取,会得到完全不同的结果,Canny算子检测出的边缘比一般微分算子更精确、更细,但也可能平滑掉一些有用的边缘。因此,在不同的条件下,应根据具体情况,选择最适合的边缘检测算子对图像进行处理,才能得到最佳效果。     

自适应多特征融合相关滤波目标跟踪

目的 针对现实场景中跟踪目标背景复杂、光照变化、快速运动、旋转等问题,提出自适应多特征融合的相关滤波跟踪算法。方法 提取目标的HOG（histogram of oriented gradients）特征和利用卷积神经网络提取高、低层卷积特征,借助一种自适应阈值分割方法评估每种特征的有效性,得到特征融合的权重比。根据权重系数融合每种特征的响应图,并据此得到目标的新估计位置,利用尺度相关滤波器计算目标尺度,得到目标尺度完成跟踪。结果 在OTB（object tracking benchmark）-2013公开数据集上进行实验,在对多特征融合进行分析的基础上,测试了本文算法在11种不同属性下的跟踪性能,并与当前流行的7种算法进行对比分析。结果表明,本文算法的成功率和精确度均排名第1,相较于基准算法DSST （discriminative scale space tracking）跟踪精确度提高了4%,成功率提高了6%。在复杂场景下比其他主流算法更具有鲁棒性。结论 本文算法以DSST相关滤波跟踪器为基准算法,借助自适应阈值分割方法评估每种特征的有效性,自适应融合两层卷积特征和HOG特征,使得判别性越强的单一特征融合权重越大,较好表达了目标的外观模型,在背景复杂、目标消失、光照变化、快速运动、旋转等场景下表现出较强的跟踪准确性。     

Robust Visual Tracking Based on Convex Hull with EMD-L1

Factors such as drastic illumination variations, partial occlusion, rotation make robust visual tracking a difficult problem. Some tracking algorithms represent a target appearances based on obtained tracking results from previous frames with a linear combination of target templates. This kind of target representation is not robust to drastic appearance variations. In this paper, we propose a simple and effective tracking algorithm with a novel appearance model. A target candidate is represented by convex combinations of target templates. Measuring the similarity between a target candidate and the target templates is a key problem for a robust likelihood evaluation. The distance between a target candidate and the templates is measured using the earth mover’s distance with L1 ground distance. Comprehensive experiments demonstrate the robustness and effectiveness of the proposed tracking algorithm against state-of-the-art tracking algorithms.     

A high performance edge detector based on fuzzy inference rules

Edge detection is an important topic in computer vision and image processing. In this paper, a novel edge detector based on fuzzy If-Then inference rules and edge continuity is proposed. The fuzzy If-Then rule system is designed to model edge continuity criteria. The maximum entropy principle is used in the parameter adjusting process. We also discuss the related issues in designing fuzzy edge detectors. We compare it with the popular edge detectors: Sobel and Canny edge detectors. The proposed fuzzy edge detector does not need parameter setting as Canny edge detector does, and it can preserve an appropriate detection in details. It is very robust to noise and can work well under high level noise situations, while other edge detectors cannot. The detector efficiently extracts edges in images corrupted by noise without requiring the filtering process. The experimental results demonstrate the superiority of the proposed method to existing ones.     

Multi-scale patch-based sparse appearance model for robust object tracking

When objects undergo large pose change, illumination variation or partial occlusion, most existing visual tracking algorithms tend to drift away from targets and even fail to track them. To address the issue, in this paper we propose a multi-scale patch-based appearance model with sparse representation and provide an efficient scheme involving the collaboration between multi-scale patches encoded by sparse coefficients. The key idea of our method is to model the appearance of an object by different scale patches, which are represented by sparse coefficients with different scale dictionaries. The model exploits both partial and spatial information of targets based on multi-scale patches. Afterwards, a similarity score of one candidate target is input into a particle filter framework to estimate the target state sequentially over time in visual tracking. Additionally, to decrease the visual drift caused by frequently updating model, we present a novel two-step object tracking method which exploits both the ground truth information of the target labeled in the first frame and the target obtained online with the multi-scale patch information. Experiments on some publicly available benchmarks of video sequences showed that the similarity involving complementary information can locate targets more accurately and the proposed tracker is more robust and effective than others.     

Using incremental subspace and contour template for object tracking

Object tracking in the presence of appearance variation and occlusion is a hot topic in research, many algorithms were proposed in recent years. Early contour tracking algorithms used particle filter in a high dimensional space. In practice, contour points can move independently, hence contour deformation forms a high dimensional deformation space. As a result, the application of particle filter is calculation expensive. In this paper, we address the problem of tracking contour in complex environments by involving subspace and a contour template. Specifically, our algorithm tracks the global motion and the local contour deformation separately. We track the global motion by weighted distance to subspace, which is adaptive to the complex environment variation by incremental learning, and then use contour model to track local deformation and evolve the contour to the edge points. The experimental results show that our method can track object contour undergoing partially occlusion and shape deforming, which verify the effectiveness of the proposed algorithm.     

结合Canny算子的图像二值化方法

用Robert、Sobel、Prewitt、Laplacian、LoG和Canny算子,对图像进行了边缘检测实验,分析了边缘检测的结果,得出Canny边缘检测算子,是图像边缘检测的一种十分有效的方法。然后,根据图像的Canny算子边缘信息,将最佳全局阈值法与局部阈值自适应法在边缘信息的基础上融合起来,对图像进行了二值化处理。实验表明此算法在二值化图像时,能很好的保留图像的边缘信息。     

一种基于猫视皮层细胞机制的改进的Sobel算子

目前最常见的边缘检测算子是Sobel算子,但是它存在对非0°和非90°朝向的边缘检测时,其输出幅度不强、抗干扰和抗亮度变化弱的问题。通过仔细比较Sobel算子与猫（以及雪貂和猴）的初级视皮层的简单细胞对场景边缘检测原理的不同,提出了更接近于猫的初级视皮层中的简单细胞的工作机制的边缘检测算法——改进的Sobel算子。实验结果表明：改进的Sobel算子不仅保留了经典的Sobel算子的优点,而且提高了45°、135°朝向的边缘输出幅度,增强了抗干扰性和亮度适应性。     

一种在低照度情况下自适应滤波牌照定位算法

提出一种在低照度情况下进行自适应滤波牌照定位算法.该方法首先设计一种×字形窗口的自适应中值滤波改进算法,对车牌灰度图像进行中值滤波滤除噪声.接着采用Sobel边缘检测器进行车牌边缘检测;再将Sobel算子卷积结果采用最大类间方差法阈值分割算法对图像进行预分割,将图像分割为目标和背景;接着采用模糊分割方法求得最终分割阈值...     

基于肤色模型和椭圆环模板的人脸跟踪及姿态估计

文章提出了一种基于肤色模型,结合椭圆环模板进行人脸跟踪及姿态估计的算法。该算法在基于肤色模型实现人脸跟踪及特征定位的过程中首先利用肤色模型定位人脸肤色区域,在跟踪中增加了自适应学习模块,使得原始的肤色模型能够在不同光照下实现自适应调整。然后利用人脸形状的先验知识,通过椭圆环模板实现人脸边缘的精确定位。最后根据所得到的面部特征和人脸边缘位置估计出人脸的姿态。实验表明,该算法能够在自然光照条件下取得较为满意的跟踪结果,同时对人脸在旋转、缩放、遮挡等条件下,多人脸背景下的跟踪有较强的鲁邦性。     

图像边缘检测的多尺度灰度Gap统计模型

汲取Hastie和Tibshiran i等人提出的“Gap statistic”的思想方法,利用样本灰度数据分布的差别定义多尺度的图像灰度间隙,在提出反分布函数概念的基础上,建立了图像边缘检测的多尺度灰度Gap统计模型。通过分析分布间隙和灰度间隙的一致性,优化了Gap统计模型的边缘检测算法。分析不同尺度下的检测结果,并比较了灰度Gap统计模型与Prew itt和Sobel边缘算子之间的相互关系。通过实例与分析,证明了该模型具有抗噪声、多尺度的特点。