共查询到18条相似文献,搜索用时 125 毫秒
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《光学学报》2015,(12)
为了检测视频序列中的遮挡边界,提出一种新颖的基于无监督在线学习的遮挡边界检测方法。该方法提取视频序列中待测帧的遮挡相关特征并计算其对应的时间长度,利用对冲算法思想并结合时间长度及不同遮挡特征求得待测帧中像素点的遮挡相关信息,利用各特征的遮挡相关信息进行投票,完成当前帧图像的遮挡边界检测。利用Online Boosting思想以当前帧的检测结果来估计下一帧的特征投票权重,实现后续帧图像的遮挡边界检测。该方法通过在线学习思想改变不同特征的权重完成遮挡边界检测功能,无需预先获取视频序列的先验知识。实验结果表明,同已有方法相比,该方法具有较高的准确性和较好的通用性。 相似文献
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为了提高动态手势检测的精确度,本文将基于YCbCr颜色空间的混合高斯背景建模应用于动态手势识别中,并且提出手势阴影消除的有效算法。首先,对待检测视频帧通过抠图抠出手势图像,在YCb'Cr'颜色空间进行椭圆拟合,统计建立椭圆肤色模型,继而在YCbCr颜色空间进行混合高斯背景建模检测出动态手势,点乘原图像得到含有阴影的RGB手势图像,对检测出的含有阴影的手势图像利用已建立的椭圆肤色模型进行阴影消除,最后将手势图像连成视频序列。实验结果表明,该算法在复杂背景下进行动态手势的检测率可达91.4%,高出传统方法10%左右,能够满足动态手势检测基本要求,且具有较高的实用价值。 相似文献
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基于柯西分布的视频图像序列背景建模和运动目标检测 总被引:7,自引:3,他引:4
提出了一种用于视觉监视系统的基于柯西分布的发光模型的光照不变变化检测方法.假定视频图像序列中每个背景图像像素点灰度观测值的时序变化由白噪声引起,利用建立的初始化背景高斯统计模型对每帧图像进行归一化,得到了背景像灰度比值的分布符合标准柯西分布的结论,解决了柯西分布的模型参量估计问题.在变化检测的基础上,YCbCr颜色空间的亮度、色调和饱和度被用来识别和消除由阴影和反光等引起的变化区域.结果表明,提出的背景建模方法对场景中各种光线变化、小的背景扰动等噪声具有稳健性,可以较为可靠地检测前景目标,识别和去除阴影和反光. 相似文献
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将传统的关键帧提取算法应用于经纬仪图像序列时,关键帧序列中会包含大量的非稳定跟踪图像帧。为了在关键帧提取过程中更好地保留目标稳定跟踪测量信息,该文在分析了经纬仪图像序列的特点后,构建了一种基于局部极大值的经纬仪图像序列关键帧提取算法。该算法首先计算图像序列的帧间差分,然后使用汉宁窗函数对帧间差分进行平滑,最后基于平滑后的帧间差分局部极大值来提取关键帧。实验结果表明:提出的算法相对于传统的帧间差分强度排序方法能更好地保留目标的跟踪测量信息,提取的关键帧在整个跟踪测量图像序列中分布更为均匀,包含的场景信息更为丰富。 相似文献
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在基于条纹投影和相位分析的三维面形测量中,由于被测物体表面标志点或复杂面形的阴影遮挡存在,会造成变形条纹局部区域的条纹数据缺失,影响相位和高度信息的最终重建,需要人为地对缺失图像信息进行修复。提出了一种新的缺失条纹数据修复方法——基于模版匹配的图像修复算法,通过图像中已有条纹信息(特别是与待修复区域周围相位信息相似度较高的已知条纹信息)对缺失的变形条纹信息进行估算,实现数据修复。该方法修复效果好,运算过程无需人为参与,便于计算机自动实现,尤其适合于待修复图像整体结构明显、纹理清晰图像的数据修复,有助于提高被测物体相位计算质量和在此基础上的三维面形重建质量。 相似文献
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在实时的虚拟场景渲染中,为减少阴影图算法由分辨率不足导致的阴影走样,提出了利用并行线性扫描的混合分辨率阴影图算法。首先,从光源视角生成高分辨率阴影图,利用并行线性扫描算法对深度均值差进行计算和分析,自底向上的合并纹素,建立纹素之间的索引关系并讨论混合分辨率阴影图的存储。在渲染阶段,利用混合分辨率阴影图进行深度测试,绘制实时的反走样阴影。实验表明,与标准阴影图相比,混合分辨率阴影图能提高20%以上的重要区域分辨率,明显改善阴影边界锯齿走样,使Dragon等模型的计算时间减少9%~18%。经实际应用验证,混合分辨率阴影图是一种有效的实时阴影绘制算法,可有效减少阴影图算法的走样。 相似文献
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水下小目标分类技术在海底探测、水下考古等方面应用广泛,在实际的水下声图像中,小目标投影产生的阴影区域通常在形状和尺寸方面显著于目标本身产生的亮区,故阴影分析算法对于目标的检测、识别和分类均有重要的研究意义。本文采用超椭圆曲线拟合算法拟合目标阴影区域,通过控制超椭圆函数的几个参数变化,实现不同的超椭圆曲线拟合不同的目标阴影形状,并将控制超椭圆曲线尺寸、形状和位置的参数作为特征向量输入到分类器,通过对比多个分类器得出分类结果,证明了以拟合参数为特征的分类方法有效。 相似文献
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One of the problems to be solved in image processing is how to eliminate image noise effectively. In this work, we brought forward a random noise filtering method based on the inter-frame registration. Firstly, we calculated the relative displacement of the adjacent frames by a registration algorithm. Then we divided the image into the overlapping area and the non-overlapping area according to the relative displacement. Finally, we do noise reduction processing for these two areas respectively. The experiments results indicate that the proposed method can reduce noise in both spatial and time domain of video images. The main advantage is that it cannot only remove noise, but also effectively protect the image edge and detail information. Besides, it not only maintains the de-noising effect of traditional inter-frame algorithm, but also is suitable for moving targets. It has better real-time performance and wider application range. 相似文献
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Shadow is one of the fundamental indicators of remote sensing image which could cause loss or interference of the target data. As a result, the detection and removal of shadow has already been the hotspot of current study because of the complicated background information. In the following passage, a model combining the Atmospheric Transport Model (hereinafter abbreviated as ATM) with the Poisson Equation, AP ShadowNet, is proposed for the shadow detection and removal of remote sensing images by unsupervised learning. This network based on a preprocessing network based on ATM, A Net, and a network based on the Poisson Equation, P Net. Firstly, corresponding mapping between shadow and unshaded area is generated by the ATM. The brightened image will then enter the Confrontation identification in the P Net. Lastly, the reconstructed image is optimized on color consistency and edge transition by Poisson Equation. At present, most shadow removal models based on neural networks are significantly data-driven. Fortunately, by the model in this passage, the unsupervised shadow detection and removal could be released from the data source restrictions from the remote sensing images themselves. By verifying the shadow removal on our model, the result shows a satisfying effect from a both qualitative and quantitative angle. From a qualitative point of view, our results have a prominent effect on tone consistency and removal of detailed shadows. From the quantitative point of view, we adopt the non-reference evaluation indicators: gradient structure similarity (NRSS) and Natural Image Quality Evaluator (NIQE). Combining various evaluation factors such as reasoning speed and memory occupation, it shows that it is outstanding among other current algorithms. 相似文献
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A novel method based on corner detectors is proposed in detecting shadow and buildings in this paper. Its most outstanding point is employing Harris corner detector in region-based detection, despite that Harris detector traditionally used to select pixels as final results. Different densities of buildings are generally influenced by different features for recognition. First time, images are self-grouped into two groups according to the distribution of buildings, and two specifical algorithms are ready for detection specifically. A region-based method is used in comparison with our algorithm, and the results indicate that the new idea works not only more robustly, but also more effectively. It is a fast and simple method, which needs average 3.28 × 10−5 s to run per square image. 相似文献
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鉴于弱小目标检测所固有的难点及常用的单一分辨率下的检测方法还不能准确稳定地检测出目标,提出了一种弱小目标检测新方法。考虑到实际应用中的复杂背景和大量干扰噪声,运用数据融合技术,先对图像进行小波多分辨率分解,然后将不同分辨率下的子图进行最优加权平均融合来检测弱小目标。用实地拍摄的空中弱小目标红外和可见光图像分别进行实验验证,实验图像取256×256像素点阵大小,其中目标占10×10像素左右。结果表明该方法能够准确稳定地检测弱小目标,为后续的跟踪作了很好的铺垫。 相似文献