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1.
针对目标跟踪过程中目标可能出现的快速变化和严重遮挡等问题,提出了一种基于新的子空间表示的目标跟踪算法。采用距离不变量对尺度不变特征变换(SIFT)特征点匹配对进行提纯。用提纯后的特征点匹配对,通过线性拟合得到仿射变化参数。在粒子滤波的理论框架下,采用快速的迭代算法,建立目标的主分量(PCA)子空间表示,结合计算得到的仿射变化参数,构造有效的目标观测模型完成跟踪。同时,采用在线学习的方法对SIFT特征点和PCA子空间进行定时更新。大量实验表明,提出的算法能快速有效地完成对姿态和形状剧烈变化的目标的精确跟踪。  相似文献   

2.
一种基于SIFT的仿射不变特征提取新方法   总被引:3,自引:1,他引:2  
图像局部特征提取是图像理解及机器视觉领域一个非常关键的问题,其中SIFT特征因具有良好的显著性和鲁棒性而得到广泛应用.但是,SIFT采用DOG检测子,定位的特征区域为各向同尺度变化的圆形区域,故其只具有尺度不变性,并不具备仿射不变性.此外,SIFT采用128维特征向量表示,当在图像特征点较多情况下进行匹配实验时,存在存储空间大、匹配耗时多等缺点.针对这两个问题,本文提出一种新的仿射不变特征提取方法,即HA-DR-SIFT(Hessian AffineDimensionality Reduction-SIFT).首先,用Hessian-Affine检测子代替DOG检测子,使提取的椭圆图像区域满足仿射不变性需求;其次,用PCA或NLPCA方法对128维特征向量进行降维处理,提高后续运算效率.实验表明,新方法不仅具有良好的仿射不变性,而且在匹配时间和存储空间上优于SIFT算子.  相似文献   

3.
以SIFT(Scale Invariant Feature Transform)算法为基础,提出了一种将局部二进制模式(Local Binary Patterns,LBP)描述子和全局上下文(Global Context)信息相融合的图像局部不变特征描述算法,增强了SIFT算法的仿射不变性,以及对处于图像相似区域的特征辨别能力。在特征检测阶段,通过迭代变换,使得SIFT特征点收敛到仿射不变点;在特征描述阶段,为每个特征点计算主方向,分别计算特征点的LBP描述子和全局上下文信息。实验结果表明,提出的局部不变特征描述子对图像仿射、尺度和旋转、光照等变换均具有良好的不变性。  相似文献   

4.
向志炎  曹铁勇  潘竟峰 《电讯技术》2012,52(8):1291-1297
针对视频序列中目标的跟踪问题,提出了一种基于粒子滤波框架的联合仿射和外貌模型的目标跟踪算法.该算法首先提取图像帧之间的相关特征点,通过求解Sylvester方程得到仿射参数,然后将仿射参数嵌入到基于仿射群的粒子滤波框架中进行平滑估计.利用基于仿射群的一阶自回归过程模拟状态的变化,联合仿射特征点模型和外貌模型进行似然估计,得到粒子的最佳平均状态,进而对目标实施跟踪.实验结果表明,在目标经历姿势和尺度变化、遮挡以及复杂背景等情况下,提出的算法能够有效地跟踪目标,较之其他相关算法具有很强的鲁棒性.  相似文献   

5.
谷帅 《信息通信》2014,(11):24-25
针对视频序列中运动目标跟踪的实时性问题,提出了一种改进的SIFT算法,即对SIFT算法生成的高维特征向量采用PCA直接进行降维。这种算法可以降低特征点的维度,提高特征点的匹配速度,计算量小,比较简单。实验结果表明该方法具有良好的实时性。  相似文献   

6.
该文针对多目标的鲁棒跟踪问题,设计了一种基于图像分水岭分割和尺度不变特征变换(SIFT)特征点的多目标全自主跟踪算法。为规避图像平坦区域,提出在原图上叠加规则坡度图的思想,并在浮点域进行一定尺度高斯模糊处理,将区域极小值点作为种子点完成分水岭分割,并将极值点作为目标特征点,通过前后帧分水岭映射生成特征点短时轨迹,自动检测运动目标。之后依据目标所处状态(是否发生遮挡)和分水岭分割图建立、更新目标SIFT特征池,结合分水岭映射、SIFT特征池匹配完成对目标的鲁棒跟踪。实验结果表明,该算法能有效完成视频中多目标的持续跟踪,并对目标遮挡有较好的鲁棒性。  相似文献   

7.
《红外技术》2018,(3):280-288
以图像匹配技术为代表的弹载电视制导技术具有信息直观的特点,作为非常优秀的图像匹配技术,SIFT算法受到了广泛的关注和深入的研究。针对传统SIFT算法实时性差的问题,本文提出了一种改进的SIFT算法。在提取特征点部分,通过Laplace算子找出图像边缘区域并进行Laplace加权处理,然后利用FAST特征点检测算法提取区域特征点;在生成特征点描述子部分,将传统的128维SIFT算子降为48维,利用改进的SIFT特征描述算子为特征点赋予方向和描述符使其具有旋转不变性;在特征点匹配部分,利用欧式距离提取匹配点对,并采用RANSAC算法提纯匹配点对,得到最优矩阵。实验结果表明改进的SIFT算法在目标旋转、尺度变化等条件下匹配效果良好,与传统SIFT算法相比具有很高的实时性,可以很好地实现图像实时匹配。  相似文献   

8.
针对传统Mean shift跟踪算法对出现遮挡的运动目标定位不准确的问题,提出一种基于Mean shift和SIFT特征的运动目标跟踪方法。首先,用Mean shift跟踪运动目标;其次,采用SIFT特征算法提取Mean shift跟踪区域的SIFT特征和上一帧目标的SIFT特征进行匹配,得到SIFT跟踪结果;最后,对融合Mean shift跟踪结果和SIFT跟踪结果。实验结果表明:提出的算法能有效跟踪遮挡的运动目标。  相似文献   

9.
基于Mean Shift的变尺度快速运动目标自适应跟踪算法   总被引:2,自引:0,他引:2       下载免费PDF全文
为了实现对变尺度快速运动目标的良好跟踪,在对传统Mean Shift跟踪算法改进的基础上,提出了一种运动目标自适应跟踪算法。该算法首先采用目标区域的像素点空域加权后的彩色图像作为初始帧目标模板,目标的真实位置利用Mean Shift算法迭代求得,从而实现对快速运动目标的空间定位,然后将相邻帧的目标采用尺度不变特征变换(SIFT)算子进行特征匹配,根据目标的缩放因子实时更新下一帧的核带宽,修正算法跟踪窗口的尺寸,以适应目标尺度的变化,从而实现对快速运动目标的尺度定位。最后,通过实验表明,与传统的Mean Shift跟踪算法相比,该算法的跟踪准确率达到97%以上,能够实现对变尺度快速运动目标的精确跟踪。  相似文献   

10.
11.
In this paper, we present a separate edge-preserving regularization scheme to calculate disparity fields for a stereoscopic image pair and a joint disparity and motion estimation algorithm for stereoscopic video sequences. We aim at using the block-based joint estimation algorithm to calculate the displacement fields for stereoscopic and multiview video coding. In the proposed separate regularization scheme, an edge-preserving cost function is proposed for matching, the Sobel edge values are incorporated into the cost function as edge-preserving weights. The optimal Lagrange multiplier is determined using the convex hull bisection algorithm under the rate-distortion theory. A fast algorithm is then proposed where the textured regions and the homogeneous regions of the images are identified and regularized differently. In the joint regularization scheme, we calculate the two motion fields and the two disparity fields for two successive image pairs simultaneously. The four fields are regularized iteratively under the stereo-motion consistency constraint. Results are compared with existing algorithms and the superior performance of the proposed methods is confirmed.  相似文献   

12.
This study concentrates on user assisted disparity remapping for stereo image footage, i.e. the disparity of an object of interest is altered while leaving the remaining scene unattended. This application is useful in the sense that it provides a method for emphasizing/de-emphasizing an object on the scene by adjusting its depth with respect to the camera. The proposed technique can also be used as a post-processing step for retargeting stereoscopic footage on different display sizes and resolutions. The proposed technique involves an MRF-based energy minimization step for interactive stereo image segmentation, for which user assistance on only one of the stereo pairs is required for determining the location of stereo object pair. A key contribution of the proposed study is elimination of dense disparity estimation step from the pipeline. This step is realized through a sparse feature matching technique between the stereo pairs. Moreover, by the help of the proposed technique, novel disparity adjusted views are synthesized using the produced stereo object segments and background information for the images. Qualitative and quantitative evaluation of the generated segments and the disparity adjusted images prove the functionality and superiority of the proposed technique.  相似文献   

13.
In stereoscopic television, there is a trade‐off between visual comfort and 3‐dimensional (3D) impact with respect to the baseline‐stretch of a 3DTV camera. It is necessary to adjust the baseline‐stretch at an appropriate distance depending on the contents of a scene if we want to obtain a subjectively optimal quality of an image. However, it is very hard to obtain a small baseline‐stretch using commercially available cameras of broadcasting quality where the sizes of the lens and CCD module are large. In order to overcome this limitation, we attempt to freely control the baseline‐stretch of a stereoscopic camera by synthesizing the virtual views at the desired location of interval between two cameras. This proposed technique is based on the stereo matching and view synthesis techniques. We first obtain a dense disparity map using a hierarchical stereo matching with the edge‐adaptive multiple shifted windows. Then, we synthesize the virtual views using the disparity map. Simulation results with various stereoscopic images demonstrate the effectiveness of the proposed technique.  相似文献   

14.
High dynamic range (HDR) images greatly improve visual content quality, but pose challenges in processing, acquisition, and display. Images captured in real-world scenarios with multiple nonlinear cameras, extremely short unknown exposure time, and a shared light source present the additional challenges of incremental baseline and angle deviation amongst the cameras. The disparity maps in such conditions are not reliable; therefore, we propose a method that relies on the accurate detection and matching of feature points across adjacent viewpoints. We determine the exposure gain among the matched feature points in the involved views and design an image restoration method to restore multiview low dynamic range (MVLDR) images for each viewpoint. Finally, the fusion of these restored MVLDR images produces high-quality images for each viewpoint without capturing a series of bracketed exposure. Extensive experiments are conducted in controlled and uncontrolled conditions, and results prove that the proposed method competes for the state-of-the-arts.  相似文献   

15.
多视点三维投影显示系统   总被引:1,自引:0,他引:1       下载免费PDF全文
费洁莹  张之江  毕家瑜   《电子器件》2008,31(1):280-284
许多人都认为自动分光立体显示技术将使得家庭视觉体验朝着更自然、更逼真的方向发展.为了营造更逼真、更刺激的 VR 效果,屏幕越大越好.本文旨在详细介绍运用在 3D 显示的多视点三维投影系统.三维图像方法的原理是视差的深度暗示.采用的方法的视差不是由于使用特殊光学眼镜或者是特殊的光学头盔作为观察光学图像形成区域而引起的.实验装置系统包括暗箱组、PC 组和一个多视点三维显示器.采用了透镜、视差栅栏来制作空间多元多视角的自动分光立体显示器.使用投影仪来模拟分光图像对.这种自动分光显示屏幕的优点在于:容易按比例放大;低成本;投影仪和屏幕间不需要精确对准.本文还研究了该屏幕的制作工艺,并给出了实验结果.  相似文献   

16.
为解决传统柱透镜自由立体投影显示中像差和视几何引起的串扰和视点数受限问题,基于回归反射,提出了一种棱镜反射光栅自由立体投影显示方法。通过分析其3D成像的原理,对棱镜反射光栅自由立体投影显示进行仿真,发现该方法在水平视宽相同的条件下,视场照度是柱透镜光栅投影的10倍,而其串扰比是柱透镜光栅投影的1/5,且不存在次视区。制作了棱镜反射光栅屏,并搭建系统进行实验,验证了棱镜反射光栅自由立体投影显示方案的可行性。  相似文献   

17.
With the emerging development of three-dimensional (3D) related technologies, 3D visual saliency modeling is becoming particularly important and challenging. This paper presents a new depth perception and visual comfort guided saliency computational model for stereoscopic 3D images. The prominent advantage of the proposed model is that we incorporate the influence of depth perception and visual comfort on 3D visual saliency computation. The proposed saliency model is composed of three components: 2D image saliency, depth saliency and visual comfort based saliency. In the model, color saliency, texture saliency and spatial compactness are computed respectively and fused to derive 2D image saliency. Global disparity contrast is considered to compute depth saliency. Particularly, we train a visual comfort prediction function to distinguish stereoscopic image pair as high comfortable stereo viewing (HCSV) or low comfortable stereo viewing (LCSV), and devise different computational rules to generate a visual comfort based saliency map. The final 3D saliency map is obtained by using a linear combination and enhanced by a “saliency-center bias” model. Experimental results show that the proposed 3D saliency model outperforms the state-of-the-art models on predicting human eye fixations and visual comfort assessment.  相似文献   

18.
狭缝光栅自由立体显示器的立体图像串扰度   总被引:3,自引:1,他引:2  
为了表征狭缝光栅自由立体显示器存在的左右眼视差图像的混叠程度,提出了立体图像串扰度C的概念。根据狭缝光栅自由立体显示器的结构和工作原理,应用几何光学知识,分析得出了立体图像串扰度C的计算公式,并给出了一个具体的狭缝光栅自由立体显示器的计算结果。通过观看实验,证明了所定义的立体图像串扰度C可以定量描述观看者在立体可视区域看到的立体图像的串扰程度。  相似文献   

19.
Stereoscopic images are generated from a pair of images (i.e., left and right images). In order to generate 3-D perception using the left and right images, it should be guaranteed that each image is perceived by the corresponding eye only. However, the depth perception becomes distorted when the left and the right eye views are interchanged, also known as a pseudoscopic problem. In this paper, we propose a novel method for detecting the pseudoscopic view by using disparity comparison in stereo images. Our approach originates from the idea that the disparities on a scene are categorized into three classes: zero disparity, positive disparity, and negative disparity, and that the foreground is usually located in front of the background. The proposed pseudoscopic view detection system consists of three sequential stages: 1) foreground/background segmentation, 2) feature points extraction, and 3) disparity comparison. We first segment the given image into two layers (i.e., foreground and background). Then, the feature points at each layer are extracted and matched to estimate the disparity characteristics of each layer. Finally, the existence of the pseudoscopic view can be investigated by using a disparity calibration model (DCM) presented in this paper and comparing the sign and magnitude of the average disparity of selected matching points set at each layer. Experimental results on various stereoscopic video sequences show that the proposed method is a useful and efficient approach in detecting the pseudoscopic view stereo images.  相似文献   

20.
Disparity field and depth map coding for multiview 3D image generation   总被引:3,自引:0,他引:3  
In the present paper techniques are examined for the coding of the depth map and disparity fields for stereo or multiview image communication applications. It is assumed that both the left and right channels of the multiview image sequence are coded using block- or object-based methods. A dynamic programming algorithm is used to estimate a disparity field between each stereo image pair. Depth is then estimated and occlusions are optionally detected, based on the estimated disparity fields. Spatial interpolation techniques are examined based on the disparity/depth information and the detection of occluded regions using either stereoscopic or trinocular camera configurations. It is seen that the presence of a third camera at the transmitter site improves the estimation of disparities, the detection of occlusions and the accuracy of the resulting spatial interpolation at the receiver. Various disparity field and depth map coding techniques are then proposed and evaluated, with emphasis given to the quality of the resulting intermediate images at the receiver site. Block-based and wireframe modeling techniques are examined for the coding of isolated depth or disparity map information. Further, 2D and 3D motion compensation techniques are evaluated for the coding of sequences of depth or disparity maps. The motion fields needed may be available as a byproduct of block-based or object-based coding of the intensity images. Experimental results are given for the evaluation of the performance of the proposed coding and spatial interpolation methods.  相似文献   

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