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《成像科学杂志》2013,61(6):332-341
AbstractThe Canny edge detection algorithm contains a number of adjustable parameters, which can affect the computation time and effectiveness of the algorithm. To overcome the shortages, this paper proposes a new way to determine the adjustable parameters and constructs a modified Canny edge detection algorithm. In the algorithm, an image is firstly smoothed by an adaptive filter that is selected based on the properties of the image, instead of a fixed sized Gaussian filter, and then, the high and low thresholds for the gradient magnitude image are determined based on maximum cross-entropy between inter-classes and Bayesian judgment theory, without any manual operation; finally, if it needs, the object closing procedure is carried out. To test and evaluate the algorithm, a number of different images are tested and analysed, and the test results are discussed. The experiments show that the studied algorithm can achieve the better edge detection results in most of the cases, and it is also useful for object boundary closing as a pre-segmentation step. 相似文献
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目的为了提高印刷图像配准的精度。方法提出一种基于梯度和归一化互信息的印刷图像配准方法。首先获取图像的归一化互信息,同时使用边缘检测算子获取图像边缘梯度的模值和方向角,然后根据边缘梯度信息和归一化互信息构造新的测度函数,以新的测度函数为目标函数,用Powell优化算法获取用于配准的最优参数。结果通过将文中提出的方法和基于归一化互信息的图像配准方法分别用于印刷图像配准,得到的统计实验结果表明,对于100项随机配准参数,新方法得出的配准误差波动幅度更小,配准精度更高。结论文中所提方法在准确性上优于基于归一化互信息的图像配准方法。 相似文献
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一种自适应的图像双边滤波方法 总被引:15,自引:0,他引:15
提出一种利用双边滤波的图像平滑滤波方法,即在滤除图像中高频噪声的同时,按照图像亮度变化保持图像中处于高频部分的边缘信息的自适应滤波过程。该滤波方法将传统的Gauss滤波器的权系数优化成Gauss函数和图像的亮度信息乘积的形式,优化后的权系数再与图像作卷积运算。这样,滤波时就可以考虑到图像的亮度信息,在滤除图像噪声的同时尽量保持了图像的边缘。由于双边滤波的方法可以使滤波器的权系数随着图像的亮度变化而改变,所以在滤波过程中能达到自适应滤波的目的。 相似文献
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基于自适应前景分割及粒子滤波的人体运动跟踪 总被引:2,自引:0,他引:2
提出了在图像序列中用自适应前景分割及粒子滤波对人体的3-D运动轨迹进行跟踪的方法.首先建立了像素点的高斯模型,并结合图像帧间的差分信息以及灰度分布的先验概率等因素完成了图像中人体的自适应分割.根据所得到的分割结果建立了透视投影下的运动平面跟踪模型.根据投影过程的非线性以及图像中噪声分布的未知性,提出了粒子滤波的跟踪方法,并最终得到了人体运动平面的3-D轨迹.实际人体运动图像序列的实验证明,本文方法能有效地跟踪人体运动的3-D轨迹,并反映出在此跟踪问题上粒子滤波比传统的扩展卡尔曼滤波更具优势. 相似文献
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基于LabVIEW的红外人体目标跟踪 总被引:1,自引:0,他引:1
针对红外图像序列信噪比低,缺少边缘及纹理信息,以及人体目标运动自主性强且姿态复杂多变的特点,选用Mean Shift目标跟踪算法,对红外人体目标进行跟踪.针对传统Mean Shift目标跟踪算法不能对尺度变化的红外目标进行有效跟踪的问题,对原有算法进行改进,使用边缘加权直方图与模板中心加权直方图计算Bhattacharyya系数的方式,实现核函数带宽的自适应,并利用界面友好的LabVIEW2011平台进行实现.通过两组实验证明了改进后算法的可行性和有效性. 相似文献
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现有加工工件材料和加工方式的多样性使得工件的表面情况多样,导致视觉系统难以准确识别工件轮廓,因此提出了一种适用于不同工件表面的轮廓识别方法。根据纹理区域面积与凸包面积的比值对工件表面进行评估和分类。对于表面质量较好的工件,采用高通线性滤波器对图像进行滤波处理,通过工件表面信息与边缘信息的差异实现工件图像边缘提取;对于表面质量较差的工件,采用一种自适应轮廓提取方法来识别图像边缘。实验表明,与传统的Canny边缘检测算法相比,所提出的方法能够更好地去除噪声干扰,其识别轮廓的精度更高。所提出的轮廓识别方法对不同工件表面有较好的适应性,具有一定的应用价值。 相似文献
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针对已知的散焦图像数学模型,通过先估计点扩散函数(PSF),然后利用维纳滤波估计原始清晰图像的方法,探讨PSF、调制传递函数(MTF)的估计方法,具体包括边缘地物法、空间频率响应法、基于APEX方法的估计算法.结合复原图像的模糊度客观评价函数和主观视觉评价来判别各方法的优劣,结果表明:边缘地物法较优. 相似文献
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玻璃小球直径的图像测量方法 总被引:2,自引:0,他引:2
提出了一种基于数字图像处理技术的微小玻璃球直径的测量方法。该方法采用Sobel算子计算目标的梯度图像,取阈值对其进行二值化处理;根据边缘成像特点,通过数学规划法计算小球边缘的初始位置;在此基础上,采用空间矩亚像素定位算法对目标边缘进行精确定位;通过拟合这些边缘点,即可求得目标直径。实验结果表明,该方法对二值化阈值的依赖性小,抗噪声能力强:在一定的范围内,阈值的不同对该算法重复精度的影响小于0.06个像素;由于采用交互方式选定处理区域,算法的计算速度较快,完成一次计算的时间不到1S。 相似文献
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In this paper, we present a deblocking algorithm that removes grid and staircase artefacts, which result from the compression of images. The KORea Multi-Purpose SATellite-2 images are efficiently compressed using an algorithm that assigns quantisation coefficients, by rows, according to local region complexity, in such a way that more complicated regions are more compressed. However, this approach is problematic in that it produces blocking artefacts in those relatively less complicated areas within the same row as the complicated regions. Removing these artefacts with a general deblocking algorithm can, undesirably, blur the complicated regions as well as the artefacts; additionally, the general filter is poor at preserving curved edges. Therefore, the algorithm proposed herein presents an adaptive filtering scheme for removing blocking artefacts while preserving image details, including curved edges, using a content analysis. Particularly, edge adaptive filtering has been introduced to remove staircase artefacts around the big image edges. Experimental analyses revealed that the proposed method outperforms several state-of-the-art approaches in terms of subjective or objective image quality, and computational speed. 相似文献
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Wei Chu John Song Theodore V. Vorburger Robert Thompson Richard Silver 《Journal of research of the National Institute of Standards and Technology》2011,116(3):647-653
Some automated bullet identification systems calculate a correlation score between two land impressions to measure their similarity. When extracting a compressed profile from the land impression of a fired bullet, inclusion of areas that do not contain valid individual striation information may lead to sub-optimal extraction and therefore may deteriorate the correlation result. In this paper, an edge detection algorithm and selection process are used together to locate the edge points of all tool-mark features and filter out those not corresponding to striation marks. Edge points of the resulting striation marks are reserved and expanded to generate a mask image. By imposing the mask image on the topography image, the weakly striated area(s) are removed from the expressed profile extraction. Using this method, 48 bullets fired from 12 gun barrels of six manufacturers resulted in a higher matching rate than previous studies. 相似文献
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目的为了有效滤除药片包装视觉检测系统中的噪声,提升图像清晰度,保证后期图像分割、边缘处理顺利进行。方法针对药片视觉检测图像中存在大量不确定噪声,提出一种自适应模糊神经网络的图像滤波算法。在模糊神经网络结构中引入一个鲁棒性较强的隶属函数,并通过梯度下降法对模糊神经网络中的参数进行优化训练,利用优化后的网络结构对被噪声污染的图像进行滤波处理。结果仿真结果表明,该算法能够在保留较完整的图像边缘和重要细节的前提下,有效滤除药片中的噪声。结论该滤波算法有效提高了药片图像的清晰度,对于后期药片图像分割以及边缘化处理具有重要意义。 相似文献
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Young Seok Han Min Kyu Park Chang Won Kim Moon Gi Kang 《International journal of imaging systems and technology》2006,16(3):92-102
Complementary color filter array (CCFA) is widely used in consumer‐level digital video cameras, since it not only has high sensitivity and good signal‐to‐noise ratio in low‐light condition but also is compatible with the interlaced scanning used in broadcast systems. However, the full‐color images obtained from CCFA suffer from the color artifacts such as false color and zipper effects. These artifacts can be removed with edge‐adaptive color interpolation (ECI) approaches which are generally used in primary color filter array (PCFA). Unfortunately, the unique array pattern of CCFA makes it difficult that CCFA adopts ECI approaches. Therefore, to apply ECI approaches suitable for CCFA to color interpolation is one of the major issues to reconstruct the full‐color images. In this paper, we propose a new ECI algorithm for CCFA. To estimate an edge direction precisely and enhance the quality of the reconstructed image, a function of spatial variances is used as a weight, and new color conversion matrices are presented for considering various edge directions. Experimental results indicate that the proposed algorithm outperforms the conventional method with respect to both objective and subjective criteria. © 2006 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 16, 92–102, 2006 相似文献