Superpixel based color contrast and color distribution driven salient object detection

Color is the most informative low-level feature and might convey tremendous saliency information of a given image. Unfortunately, color feature is seldom fully exploited in the previous saliency models. Motivated by the three basic disciplines of a salient object which are respectively center distribution prior, high color contrast to surroundings and compact color distribution, in this paper, we design a comprehensive salient object detection system which takes the advantages of color contrast together with color distribution and outputs high quality saliency maps. The overall procedure flow of our unified framework contains superpixel pre-segmentation, color contrast and color distribution computation, combination, and final refinement.In color contrast saliency computation, we calculate center-surrounded color contrast and then employ the distribution prior in order to select correct color components. A global saliency smoothing procedure that is based on superpixel regions is introduced as well. This processing step preferably alleviates the saliency distortion problem, leading to the entire object being highlighted uniformly. Finally, a saliency refinement approach is adopted to eliminate artifacts and recover unconnected parts within the combined saliency maps.In visual comparison, our method produces higher quality saliency maps which stress out the total object meanwhile suppress background clutter. Both qualitative and quantitative experiments show our approach outperforms 8 state-of-the-art methods, achieving the highest precision rate 96% (3% improvement from the current highest), when evaluated via one of the most popular data sets. Excellent content-aware image resizing also could be achieved using our saliency maps.     

Finding spatio-temporal salient paths for video objects discovery

Many videos capture and follow salient objects in a scene. Detecting such salient objects is thus of great interests to video analytics and search. However, the discovery of salient objects in an unsupervised way is a challenging problem as there is no prior knowledge of the salient objects provided. Different from existing salient object detection methods, we propose to detect and track salient object by finding a spatio-temporal path which has the largest accumulated saliency density in the video. Inspired by the observation that salient video objects usually appear in consecutive frames, we leverage the motion coherence of videos into the path discovery and make the salient object detection more robust. Without any prior knowledge of the salient objects, our method can detect salient objects of various shapes and sizes, and is able to handle noisy saliency maps and moving cameras. Experimental results on two public datasets validate the effectiveness of the proposed method in both qualitative and quantitative terms. Comparisons with the state-of-the-art methods further demonstrate the superiority of our method on salient object detection in videos.     

Bayesian salient object detection based on saliency driven clustering

Salient object detection is essential for applications, such as image classification, object recognition and image retrieval. In this paper, we design a new approach to detect salient objects from an image by describing what does salient objects and backgrounds look like using statistic of the image. First, we introduce a saliency driven clustering method to reveal distinct visual patterns of images by generating image clusters. The Gaussian Mixture Model (GMM) is applied to represent the statistic of each cluster, which is used to compute the color spatial distribution. Second, three kinds of regional saliency measures, i.e, regional color contrast saliency, regional boundary prior saliency and regional color spatial distribution, are computed and combined. Then, a region selection strategy integrating color contrast prior, boundary prior and visual patterns information of images is presented. The pixels of an image are divided into either potential salient region or background region adaptively based on the combined regional saliency measures. Finally, a Bayesian framework is employed to compute the saliency value for each pixel taking the regional saliency values as priority. Our approach has been extensively evaluated on two popular image databases. Experimental results show that our approach can achieve considerable performance improvement in terms of commonly adopted performance measures in salient object detection.     

显著区域检测算法综述

检测视觉上显著的区域对于很多计算机视觉应用都是非常有帮助的,例如：内容保持的图像缩放,自适应的图像压缩和图像分割。显著区域检测成为视觉显著性检测领域的重要研究方向。文中介绍了显著区域检测算法的研究现状并分析了典型的显著区域检测方法。首先,将现有的显著区域检测算法进行了分类和分析。然后,在一个包含1000幅图像的公开数据集上对典型的显著区域检测算法进行了评测。最后对现有的显著区域检测算法进行了总结并展望了下一步发展方向。     

面向显著性目标检测的SSD改进模型

传统显著性目标检测方法常假设只有单个显著性目标,其效果依赖显著性阈值的选取,并不符合实际应用需求。近来利用目标检测方法得到显著性目标检测框成为一种新的解决思路。SSD模型可同时精确检测多个不同尺度的目标对象,但小尺寸目标检测精度不佳。为此,该文引入去卷积模块与注意力残差模块,构建了面向多显著性目标检测的DAR-SSD模型。实验结果表明,DAR-SSD检测精度显著高于SOD模型;相比原始SSD模型,在小尺度和多显著性目标情形下性能提升明显;相比MDF和DCL等深度学习框架下的方法,也体现了复杂背景情形下的良好检测性能。     

基于特征排列和空间激活的显著物体检测方法

显著物体检测目前在计算机视觉领域中非常重要,如何处理不同尺度的特征信息成为能否获得优秀预测结果的关键。该文有两个主要贡献,一是提出一种用于显著目标检测的特征排列方法,基于自编码结构的卷积神经网络模型,利用尺度表征的概念将特征图进行分组和重排列,以获得一个更加泛化的显著目标检测模型和更加准确的显著目标预测结果;二是在输出部分利用了双重卷积残差和FReLU激活函数,抓取更全面的像素信息,完成空间信息上的激活。利用两种算法的特点融合作用于模型的学习训练。实验结果表明,将该文算法与主流的显著目标检测算法进行比较,在所有评测指标上都达到了最优的效果。     

基于多特征扩散方法的显著性物体检测

现有的大部分基于扩散理论的显著性物体检测方法只用了图像的底层特征来构造图和扩散矩阵,并且忽视了显著性物体在图像边缘的可能性。针对此,该文提出一种基于图像的多层特征的扩散方法进行显著性物体检测。首先,采用由背景先验、颜色先验、位置先验组成的高层先验方法选取种子节点。其次,将选取的种子节点的显著性信息通过由图像的底层特征构建的扩散矩阵传播到每个节点得到初始显著图,并将其作为图像的中层特征。然后结合图像的高层特征分别构建扩散矩阵,再次运用扩散方法分别获得中层显著图、高层显著图。最后,非线性融合中层显著图和高层显著图得到最终显著图。该算法在3个数据集MSRA10K,DUT-OMRON和ECSSD上,用3种量化评价指标与现有4种流行算法进行实验结果对比,均取得最好的效果。     

Boosting算法在入侵检测中的应用

将一种基于支持向量机的Boosting算法应用于入侵检测,并通过KDD’99数据的仿真实验将它与单一的支持向量机分类器进行比较,结果表明Boosting算法比单一的支持向量机分类器具有更好的检测效果。     

基于多图神经网络协同学习的显著性物体检测方法

目前基于深度卷积神经网络的显著性物体检测方法难以在非欧氏空间不规则结构数据中应用,在复杂视觉场景中易造成显著物体边缘及结构等高频信息损失,影响检测性能。为此,该文面向显著性物体检测任务提出一种端到端的多图神经网络协同学习框架,实现显著性边缘特征与显著性区域特征协同学习的过程。在该学习框架中,该文构造了一种动态信息增强图卷积算子,通过增强不同图节点之间和同一图节点内不同通道之间的信息传递,捕获非欧氏空间全局上下文结构信息,完成显著性边缘信息与显著性区域信息的充分挖掘;进一步地,通过引入注意力感知融合模块,实现显著性边缘信息与显著性区域信息的互补融合,为两种信息挖掘过程提供互补线索。最后,通过显式编码显著性边缘信息,指导显著性区域的特征学习,从而更加精准地定位复杂场景下的显著性区域。在4个公开的基准测试数据集上的实验表明,所提方法优于目前主流的基于深度卷积神经网络的显著性物体检测方法,具有较强的鲁棒性和泛化能力。     

Robust player detection and tracking in broadcast soccer video based on enhanced particle filter

It is significant to detect and track soccer players in broadcast sports video, which is helpful to analysis player activity and team tactics. However, it is challenging to efficiently detect and track soccer players with shots switched and noise caused by auditorium and billboards. And for multi-player tracking how to treat the increase or decrease of player are also difficult. In this paper, a robust player detection algorithm based on salient region detection and tracking based on enhanced particle filtering are proposed. Salient region detection is used to segment sports fields, and then soccer players are detected by edge detection combined with Otsu algorithm. For soccer players tracking, we use an enhanced particle filter which we improve the algorithm in sample and the likelihood function combing the color feature and edge feature. Experimental results show the proposed algorithm can quickly and accurately detect and track soccer players in broadcast video.     

基于加权的K近邻线性混合显著性目标检测

显著性目标检测旨在于一个场景中自动检测能够引起人类注意的目标或区域,在自底向上的方法中,基于多核支持向量机(SVM)的集成学习取得了卓越的效果。然而,针对每一张要处理的图像,该方法都要重新训练,每一次训练都非常耗时。因此,该文提出一个基于加权的K近邻线性混合(WKNNLB)显著性目标检测方法：利用现有的方法来产生初始的弱显著图并获得训练样本,引入加权的K近邻(WKNN)模型来预测样本的显著性值,该模型不需要任何训练过程,仅需选择一个最优的K值和计算与测试样本最近的K个训练样本的欧式距离。为了减少选择K值带来的影响,多个加权的K近邻模型通过线性混合的方式融合来产生强的显著图。最后,将多尺度的弱显著图和强显著图融合来进一步提高检测效果。在常用的ASD和复杂的DUT-OMRON数据集上的实验结果表明了该算法在运行时间和性能上的有效性和优越性。当采用较好的弱显著图时,该算法能够取得更好的效果。