共查询到20条相似文献,搜索用时 194 毫秒
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王春芳 《计算机测量与控制》2014,22(8):2663-2665
为解决随机Hough变换中无效采样和累积问题,研究了一种基于空间矩的随机Hough变换直线检测方法;利用空间矩方法进行随机采样并求取出参数空间点,将计算参数空间点的随机采样点减少到一个,最后利用随机Hough变换原理来确定真实直线;实验结果表明,基于空间矩的随机Hough变换直线检测方法相对于传统的随机Hough变换具有更好的准确性、鲁棒性和稳定性,实时性得到了较大的提高。 相似文献
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改进的随机Hough变换圆检测算法 总被引:2,自引:0,他引:2
针对随机Hough变换会产生大量无效累积的问题,提出了一种改进的随机Hough变换算法来检测圆,该算法利用梯度来预先判断随机采样的三个点是否在同一个圆上,从而大大减少了无效累积;另外,该算法还在圆参数的计算、阈值的确定、候选圆的确认等方面进行了改进.实验结果表明,该算法精度高,速度快,检测性能有了较大提高. 相似文献
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王春芳 《计算机工程与设计》2015,(3):716-720
为实现角点的有效检测,提高检测速度,提出一种基于随机 Hough变换的角点检测方法。利用随机 Hough变换求取出直线参数;根据角点在 Hough空间中的特征,利用反 Hough变换的反演原理对参数空间中的峰值进行反变换,定位图像空间中的直线交点;为避免虚假角点,将那些附近不包含任何边缘的交点删除,得到正确的角点。实验结果表明,该方法相对于 Harris算法和SUSAN具有更好的准确性、鲁棒性和稳定性,实时性也有一定提高。 相似文献
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《计算机辅助设计与图形学学报》2014,(8)
Hough变换因其固有的鲁棒性在众多视觉问题中得到了广泛应用.文中探讨了当Hough变换的参数空间均匀离散化后,如果要求不同的直线对应不同的计数器,则对应的离散参数空间所需的最少计数器个数的问题.以Hough变换的标准参数(ρ,θ)空间为例进行探讨,相关方法完全可以推广到Hough变换的其他参数化形式.文中的结果从一个侧面揭示了图像均匀噪声在Hough变换参数空间分布的固有的不均匀性现象,这种不均匀性必然导致Hough变换在直线检测时直线位置和朝向的依赖性对噪声的不同敏感程度,该结果对从事Hough变换研究的相关人员具有一定的参考作用. 相似文献
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基于经典Hough变换提出了一种改进的随机Hough变换算法,该算法可以大大提高识别速度和检测精度,减小存储空间,降低运算量,且仍具有经典Hough变换对噪声不敏感,随机Hough变换随机抽样和多对一收敛映射的特点,实现了一种逐次提取曲线的方法,将曲线按照由长到短的顺序依次提取出来,并给出了曲线的起始点和终止点的计算方法,实验证明了方法的有效性。在此基础上,还对形状不变性特征进行了分析,得出图形平移、旋转、缩放后,Hough变换峰值的个数没有改变,对角度归一化后,峰值的初始位置有所变化,但峰值间的间隔没有变化。 相似文献
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基于弦中点Hough变换的同心圆检测方法 总被引:3,自引:0,他引:3
给出了一种基于Hough变换的同心圆检测方法,其核心思想是降低经典Hough变换圆检测中的Hough累积维数,将经典Hough变换圆检测时的三维参量统计,转变成基于弦中点的圆心和半径的参量统计。根据圆上所有点的内切圆必经过圆中心的事实,提取黑白边缘图像来建立二维数组累加器,依照像素点分布扫描边缘图像,累加器计数,计算出圆心位置,对每个圆心进行半径累积,确定同心圆半径集。与经典的Hough变换检测方法相比,该方法降低了计算复杂度。 相似文献
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随机Hough变换是一种检测圆的有效方法.为了进一步提升随机Hough变换圆检测算法的执行速度和抗噪声能力,提出一种基于有效继承的随机Hough变换圆检测累计加速算法.该算法在每次成功检测圆后不清空参数空间的累计值,继承了上次的有效采样,对没有通过验证的参数单元设定负累计值;通过数理统计分析,采用伯努利试验模型解释了加速原理,得出该算法可以减少总采样次数并节省清空参数空间所需时间的结论.实验结果表明,加速原理的理论分析是正确的,文中算法的加速效果是显著的,且具备更强的抗噪声能力. 相似文献
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角点特征没有参数化的描述方式,无法应用传统的Hough变换转换到参数空间进行检测.文中提出一种Monte Carlo框架下的随机角点检测方法,不是在参数空间中求解,而是将角点检测转换为交点累积空间中寻找局部极值的问题.交点累积空间是根据角点实质是直线交点的特征提出的一种概念.文中证明了算法的思想,推导了算法的具体步骤.... 相似文献
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Shenghua Xu Jiping Liu Yong Wang Litao Han Yunsheng Zhang 《International journal of remote sensing》2013,34(23):8315-8330
Considering the low efficiency and accuracy of existing straight line extraction methods from large-scale imagery, a multi-scale Hough transform (HT) method based on the pre-storage weight matrix is proposed. Improvements of the proposed HT include: using the pre-storage weight matrix to save storage space and improve the efficiency of the HT, applying a multi-scale method to enable the detection of smaller features from large-size images, using overlapping adjacent tiles to avoid the fragmented lines, optimizing the dimensions of the discrete transform domain, normalizing the accumulator to extract off-centred lines and using a dual threshold for distributed line detection. The experimental results show that the proposed algorithm is not only more efficient and robust but also can obtain richer and more accurate information about features, especially for large-size images. 相似文献
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提出了一种适用于TDI-CIS(时间延迟积分CMOS图像传感器)的模拟域流水采样列级运放共享累加器结构。提出的这种模拟累加器结构应用流水采样结构在不改变运放速率的前提下,将累加器的速率提升为传统累加器的2倍;采用积分电容列运放共享技术将n级TDI-CIS所需的运放个数减少至采用传统累加器所需个数的1/n。分析了流水采样累加器结构的原理以及输出噪声。使用标准0.18μm CMOS工艺进行了电路设计。仿真结果显示,提出的模拟累加器结构功耗为0.29 mW,采样率为2 Msample/s。结果表明流水采样列级运放共享累加器结构在保持低电路面积和功耗的同时,可将TDI-CIS最大可达到的行频增加一倍,更适于高速扫描的应用环境。 相似文献
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为实现井壁图像上平面地质特征的自动提取,研究了图像中单周期正弦曲线的检测方法。提出一种改进的霍夫变换,该方法基于正弦曲线上的三个相关联点在二维累加器中进行投票,从而确定相位与基线深度;然后在一维累加器中投票,确定振幅。对模拟图像及井壁图像进行了处理,并与传统霍夫变换、快速霍夫变换进行了对比。结果表明,该方法不仅提高了检测速度,而且具有较高的准确率。 相似文献
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《Computers & Electrical Engineering》2014,40(8):26-36
Object detection is a critical step of many image recognition systems. In this paper, we discuss the problem of circular shape object detection in still color images. An isotropic edge detector merged with spatial information and region based analysis is employed to extract image edge and obtain accurate gradient information of edge pixels, which assures the high accuracy of the subsequent circle detection. Then three circle parameters are estimated efficiently with only one 2-dimensional accumulator array and one 1-dimensional accumulator array, which greatly reduces the storage requirements and time complexity of our approach. Experimental results show that our method is robust in locating objects with complete or incomplete or concentric circle boundary in real color images without any prior knowledge. 相似文献
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基于改进的多分辨率Hough变换的直线检测方法 总被引:2,自引:1,他引:2
该文提出了一种基于改进的多分辨率Hough变换的直线检测方法。对多分辨率图像由粗到细地循环处理,首先利用全局累加器序列对最小的图像做Hough变换得直线参数,利用该直线参数估计下一循环图像中的直线参数;建立了一种简单对应关系,将得到的直线参数的估计范围转换成图像空间范围;然后在图像空间范围内利用局部累加器对较大图像做Hough变换检测直线。最后还给出了线段端点检测、长度计算及连续性考察的方法。实验表明,该方法可以加快直线检测速度、节省存储空间,端点检测方法具有一定的鲁棒性。 相似文献
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The Hough transform (HT) is widely used for feature extraction and object detection. However, during the HT individual image elements vote for many possible parameter values. This results in a dense accumulator array and problems identifying the parameter values that correspond to image features. This article proposes a new method for implementing the voting process in the HT. This method employs a competitive neural network algorithm to perform a form of probabilistic inference known as “explaining away”. This results in a sparse accumulator array in which the parameter values of image features can be more accurately identified. The proposed method is initially demonstrated using the simple, prototypical, task of straight line detection in synthetic images. In this task it is shown to more accurately identify straight lines, and the parameter of those lines, compared to the standard Hough voting process. The proposed method is further assessed using a version of the implicit shape model (ISM) algorithm applied to car detection in natural images. In this application it is shown to more accurately identify cars, compared to using the standard Hough voting process in the same algorithm, and compared to the original ISM algorithm. 相似文献
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提出了傅里叶最小二乘法对卷积伏安数据的处理,经过参数优化后,处理后的伏安数据可以用于进一步的卷积伏安运算中,处理后的估安波形未发生变形,峰位置准确。 相似文献
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Philippe Camacho Alejandro Hevia Marcos Kiwi Roberto Opazo 《International Journal of Information Security》2012,11(5):349-363
Accumulator schemes were introduced in order to represent a large set of values as one short value called the accumulator. These schemes allow one to generate membership proofs, that is, short witnesses that a certain value belongs to the set. In universal accumulator schemes, efficient proofs of non-membership can also be created. Li et?al. (Proceedings of applied cryptography and network security—ACNS ’07, LNCS, vol 4521, 2007), building on the work of Camenisch and Lysyanskaya (Advances in cryptology—proceedings of Crypto ’02, LNCS, vol 2442. Springer, Berlin, pp 61–76, 2002), proposed an efficient accumulator scheme, which relies on a trusted accumulator manager. Specifically, a manager that correctly performs accumulator updates. In this work, we introduce the notion of strong universal accumulator schemes, which are similar in functionality to universal accumulator schemes, but do not assume the accumulator manager is trusted. We also formalize the security requirements for such schemes. We then give a simple construction of a strong universal accumulator scheme, which is provably secure under the assumption that collision-resistant hash functions exist. The weaker requirement on the accumulator manager comes at a price; our scheme is less efficient than known universal accumulator schemes—the size of (non)membership witnesses is logarithmic in the size of the accumulated set in contrast to constant in the scheme of Camenisch and Lysyanskaya. Finally, we show how to use strong universal accumulators to solve a problem of practical relevance, the so-called e-Invoice Factoring Problem. 相似文献
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利用局部算子检测峰值的改进Hough变换算法* 总被引:2,自引:0,他引:2
提出了一种改进的峰值检测算法,将累加器空间视为一幅二维图像,利用局部算子区增强期望的直线和噪声对应的峰值之间的差别;利用最小二乘法拟合增强后的累加器空间对应的分布直方图,得到具有更强鲁棒性的阈值来确定期望峰值所在的位置。实验结果表明,该算法同时具有较高的精度和较强的鲁棒性,对先验知识的需求很低,具有较好的通用性,为自主应用方式奠定了基础。 相似文献