共查询到19条相似文献,搜索用时 250 毫秒
1.
为了能在模糊或有噪声的图像中直接检测角点,提出了一种对比多尺度下灰度差异几何特征和搜索局部灰度最大权值的角点检测方法。该方法根据图像中角点位置的灰度差异,采用多尺度圆形检测器遍历图像,对比不同尺度下检测器所得到的几何参数来初步确定角点位置并剔除边缘附近的伪角点;根据局部灰度权值最大原则去除由于圆形检测器的离散性而聚集在真角点周围伪角点,并确定角点的最终位置。实验结果表明,相对于传统算法,该方法能够在对噪声或模糊图像不做预处理的情况下检测出角点。 相似文献
2.
提出了一种新的SUSAN-Laplace角点算子。新算子首先使用拉普拉斯-高斯核对图像进行卷积,并将图像转换为二值或三值图像,然后使用SUSAN算子检测角点。这样既快速又具有SUSAN算子的位置精确性。SUSAN- Laplace角子具有较好的旋转、仿射、光照、尺度和噪声不变性,其计算速度也较快,比Harris角点快1.5倍,比SUSAN角点快6倍。应用中SUSAN-Laplace角子有一种快速算法,快速算法在计算拉普拉斯-高斯卷积时使用移位运算代替全部乘除法运算,能进一步提高计算速度。SUSAN-Laplace角子较其它角点算法能产生更丰富的角点,应用到SIFT算法中可提高对小目标的识别能力。 相似文献
3.
本文基于三坐标测量机(CMM)设计了一套视觉检测系统,该系统能够对零件实际空间特征信息进行比较全面地提取。针对位于CMM平台上带有角点的零件,利用Harris算子提取从CMM三个不同方位获取的零件图像的角点。对于Harris算子提取到的角点,本文提出一种八链码搜索法和SUSAN区域法相结合的伪角点剔除方法,最后基于立体视觉的原理,提出"距离空间图"匹配算法,将以上3幅图像一一建立匹配关系。实验中多次改变零件在CMM中姿态时,多次实验数据表明本文的角点提取精度与真实角点间仅存在1~2像素的偏差,零件的定位误差为1~3 mm。通过实验验证,角点匹配和定位的稳定性和精度满足要求,具有一定的抗干扰性和实用性。 相似文献
4.
5.
6.
7.
8.
本文提出了一种结合Harris与SIFT算子的快速图像配准方法。首先,对Harris算法进行两方面的改进:一是构建高斯尺度空间,提取具有尺度不变性的角点特征;二是采用Forsnter算子对提取的角点精定位,提高配准精度。然后,利用SIFT算子的特征描述方法描述提取到的特征点,通过随机kd树算法对两幅影像的特征点进行匹配。最后采用RANSAC算法对匹配点对进行提纯,并通过最小二乘法估计两幅影像间的空间变换单应矩阵,完成图像配准。实验结果表明:本文方法在基本保持配准精度的同时,在配准过程的时间消耗上比标准SIFT算法减少了64%。 相似文献
9.
在线结构光三维测量系统中,高精度激光条纹中心线提取是提高测量精度的关键。针对现有激光中心线存在提取精度不高、保留细节差等问题,提出了一种基于法线引导的激光中心线提取算法。该算法具体实现步骤为:首先,对图像进行预处理,结合边缘检测和几何中心法对激光线初步提取;然后,用主成分分析法(principal component analysis,PCA)求取其法线,在激光中心点处划分角度八邻域,通过法线角度引导搜寻有效点集;最后,利用灰度重心法对点集进行亚像素提取。实验结果表明:该算法均方根误差与灰度重心法相比提高了0.233 9像素,比Steger算法、方向模板法更好地保留了光条细节,可以更精确地提取光条中心,达到亚像素级的精度。 相似文献
10.
11.
12.
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
13.
Fingerprint image enhancement using multi-scale DDFB based diffusion filters and modified Hong filters 总被引:1,自引:0,他引:1
The main task of a fingerprint image enhancement is to enhance the image in such a way that it not only remove the noise but also enhance the reliable minutiae points. For this purpose, in this paper we propose a multi-scale decimation-free directional filter bank method for reliable orientation estimation. This reliable orientation is used in coherence enhancement diffusion and in Gabor filter based enhancement, which overcomes the drawbacks of these two methods. Experimental results show that the proposed method not only enhances the images but also facilitates the minutiae algorithm, by enhancing the true minutiae points. 相似文献
14.
An improved Harris corner detection algorithm is proposed based on Barron operator, since Harris corner detection algorithm has a poor accuracy in positioning complex corner detection and may miss certain real corners. Firstly, the image gradient is calculated by using Barron operator to reduce the calculation errors from Prewitt operator or Sobel operator. Secondly, the centre B-spline function is used to smooth image, filter noise, and retain the corners information better. Thirdly, a non-maximal inhibition and corners sieving method is used to determine whether the detected corners are real corners or not. A square window is centered at the pixel and eliminate the corner if the value of the corner response function is non-maximal in the window. And then divide the test image into several blocks so as to process each block independently, and use a cyclic iterative method to determine the threshold value to make sure that the real corners are accurately selected. Finally, experiments indicate the algorithm has relatively great noise proof ability and is able to extract complex corners effectively. 相似文献
15.
16.
17.
Xiangzhi Bai 《Optik》2013
To efficiently extract all the possible linear features in image, a multi-scale multi-structuring element top-hat by reconstruction operator based algorithm with simple post-processing is proposed in this paper. Multi-scale top-hat by reconstruction operator using multi-scale structuring elements is discussed, firstly. Also, through importing multi-structuring elements with linear shapes at different directions, multi-scale multi-structuring element top-hat by reconstruction operator for linear feature extraction is shown. By using the multi-scales of multi-structuring elements, the method of extracting all the possible linear feature regions in an image is proposed. After extracting the linear feature regions, the final detected linear features, which are expressed as lines with different shapes and lengths, are obtained through image binarisation and refinement. Experimental results on different types of images show that, the proposed algorithm is efficient for linear feature detection and could be widely used in different applications related to multiple linear feature detection. 相似文献
18.
This paper investigates the misplacement issue presented on the detection of feature points by using the well-known Harris detector, under several watermarking attacks. Harris detector, as a powerful tool in finding image's points of high importance, called “interest points”, has been widely used to locate specific image portions where watermarks are embedded, according to some watermarking insertion procedure. Although Harris detector constitutes a significant part of a typical feature-based watermarking process, no work dealing with its performance under certain attacks has been reported yet. This work studies the accuracy of Harris detector in finding the feature points, which define the watermarked regions of attacked images, firstly as an individual processing module and secondly as a part of a feature-based watermarking methodology. Detailed theoretical analysis followed by appropriate simulation experiments has shown that the incorporation of the Harris detector into the watermarking procedure presents misplacement issues that can lead the watermarking algorithm to unreliable results. In the way of decreasing these misplacement errors, a novel algorithm that extracts more stable interest points, with promising performance is also proposed. 相似文献
19.
基于局部光流约束的角点匹配算法 总被引:2,自引:1,他引:1
提出了一种基于局部光流约束的角点匹配算法。首先采用Harris算子获得当前帧和参考帧的角点,然后以角点的光流特征作为约束条件,根据两帧图像角点集的坐标分布,排除异常角点,完成角点的精确匹配,实现图像之间的高精度运动估计。通过对视频序列进行实验,采用差图法可主观地发现该运动估计算法的有效性;以峰值信噪比作为评价指标,发现原始视频序列的帧间峰值信噪比明显低于仿射视频序列的帧间峰值信噪比。前者的平均值为22.8072,后者的平均值为33.3854,从而客观地说明了该算法的有效性和稳定性。 相似文献