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1.
D.-M. Tsai C.-P. Lin 《The International Journal of Advanced Manufacturing Technology》2002,20(9):664-675
In this paper, we present a fast machine vision method for the automatic inspection of defects in textured surfaces. Traditional
2D Gabor filtering schemes have been shown to be very effective for detecting local anomalies in textured surfaces of industrial
materials. However, they are computationally expensive and sensitive to image rotation. In order to alleviate the limitations
of 2D Gabor filtering, we first use a 1D ring-projection transformation to compress a 2D grey-level image into a 1D pattern,
and then employ a 1D Gabor filter to detect defects embedded in a homogeneous texture. Given a problem with image size N × N and filter window W × W, the computational complexity can be reduced significantly from O(W
2
N
2
) in the 2D Gabor space to O(WN
2
) in the 1D Gabor space, and the detection results are invariant to rotation changes of a texture. The experiments on structural
textures such as a wooden surface, an LCD display, and a machined surface, and statistical textures such as granite, leather,
and sandpaper have shown the efficiency and effectiveness of the proposed method.
ID="A1" Correspondence and offprint requests to: Dr Du-Ming Tsai, Department of Industrial Engineering and Management, Yuan-Ze University, 135 Yuan-Tung Road, Nei-Li, Tao-Yuan,
Taiwan. E-mail: iedmtsai@saturn.yzu.edu.tw 相似文献
2.
针对印刷电路板裸板缺陷在线视觉检测,提出了一种适用于电路板彩色图像的缺陷检测算法。该算法主要通过分析缺陷区域边界像素的梯度方向信息获得对应的典型图像特征,具体由滤波去噪、目标分割和特征提取三部分组成。为减弱环境光干扰同时保证边缘细节的清晰,首先在CIE Lab色彩空间对图像进行双边滤波,然后利用该色彩空间的均匀性分割出需要检测的目标区域,最后设计了邻域梯度方向信息熵这一描述子用于提取缺陷特征和构造特征向量,利用支持向量机对缺陷进行识别。实验结果表明:所提算法能够对印刷电路板裸板存在的短路、断路、孔洞、余铜、划痕等常见缺陷进行快速精确的定位,能够满足生产过程中的实时检测要求。 相似文献
3.
Automated Surface Inspection Using Gabor Filters 总被引:10,自引:2,他引:10
D.-M. Tsa S.-K. Wu 《The International Journal of Advanced Manufacturing Technology》2000,16(7):474-482
In this paper we present a machine vision system for the automatic inspection of defects in textured surfaces found in industry.
The defects to be inspected are those that appear as local anomalies embedded in a homogeneous texture. The proposed method
is based on a Gabor filtering scheme that computes the output response of energy from the convolution of a textured image
with a specific Gabor filter. The best parameters of a Gabor filter are selected so that the energy of the homogeneous texture
is zero, and any unpredictable defeats will generate significantly large energy values. A simple thresholding scheme then
follows to discriminate between homogeneous regions and defective regions in the filtered image. This transforms texture differences
into detectable filter output. The experiments on structural textures such as leather and sandpaper have shown the effectiveness
of the proposed method. 相似文献
4.
针对机械系统中近似高斯分布的低信噪比时间序列,设计出一种用于异常检测的参数可调熵滤波器。为检测均值漂移和方差变动这两类统计特性异常,对基于滑动窗的Shannon熵滤波器的参数设置策略进行研究。引入单调因子K1,在保证滤波器工作单调性的同时,可以获取不同的平滑效果。通过引入尺度因子K2,实现对熵滤波器正常信号容限的调节,从而实现时间序列的可变尺度异常检测。以时间序列中异常信号与正常信号统计特性重合度在滤波前后之比作为滤波器性能评价指标,利用仿真信号分析两个参数在检测均值漂移和方差变动异常时的合理取值范围。对电子清纱器颜色异纤信号的检测试验结果表明,这种带参数的熵滤波器对近似高斯分布的时间序列信号具有良好的异常检测能力。 相似文献
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将信息熵引入到图像的边缘检测中,利用数据Gap统计方法的思想,提出了熵差的概念,建立了一种基于熵差的二值图像边缘检测模型,给出了边缘检测的算法,并通过图像边缘检测实例,与经典的sobel边缘检测法进行了比较。 相似文献
8.
M. S. Packianather P. R. Drake 《The International Journal of Advanced Manufacturing Technology》2000,16(6):424-433
A decision tree using smaller more specialised modular neural networks for the classification of wood veneer by an automatic
visual inspection system was presented in Part 1 [1]. A key process in the design of a modular neural network is the use of
"normalised inter-class variation" in the selection of the most appropriate image features to be used for its particular specialised
classification task. At the root of the decision tree is a single large (holistic) neural network that initally attempts to
classify all of the image classes which include clear wood and 12 possible defects (13 classes). The initial design uses 17
features of the acquired image of the wood veneer as inputs. The selection (or more correctly pruning) of inputs for this
large neural network used not only "normalised inter-class variation", but also "normalised intra-class variation" in the
features and their "correlation" within the same class. This results in the elimination of 6 inputs. The revised smaller 11
input neural network results in a substantial reduction in classification time, for the computer implementation used here,
and at the same time the classification accuracy is improved. This is the root of the decision tree described in the previous
paper. 相似文献
9.
基于数字图像处理和特征提取的钢轨表面缺陷识别方法 总被引:1,自引:0,他引:1
设计了一种基于图像特征分析的钢轨表面缺陷识别方法,运用快速数字图像处理技术可实现钢轨表面裂缝和剥离掉块缺陷的提取,该识别方法通过对采样图像使用高低帽变换进行图像增强,再进行高斯平滑消除毛刺,最后采用阈值处理及边界抑制来提取出缺陷信息。研究了钢轨伤损评价及信息表达方法,可将缺陷信息以曲线的形式表示出来。为验证所设计方法的有效性,设计了模拟实验装置,用工业线阵CCD摄像机获取钢轨样品运动时检测的图像,进行缺陷识别处理,实验表明,系统输出曲线能够明确反映损伤的程度及其位置信息。 相似文献
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为提高对焊缝缺陷的检测精度,提出采用支持向量机(Support Vector Machine,SVM)分类的方法对X射线焊缝图像进行分割.选择训练样本图像的灰度、形态学梯度作为训练向量的特征分量对SVM进行训练,得到SVM分割模型后,将测试样本输入分割模型进行分割处理.以气孔缺陷为例,证明了该方法能实现焊缝气孔缺陷的准确分割,与其他分割方法相比,可提高缺陷检测的精度. 相似文献
12.
对自由曲面用带角圆柱铣刀3轴NC加工提出了系统的刀具干涉检测方法。加工自由曲面时,刀具干涉可以出现在包括刀具驱动面的刀具周围的任何地方。本文提出先检测自由曲面上可能产生刀具干涉的区域,然后再生成刀具路径,这样不但可极大地简化安排刀具路径的过程,改善加工的精度和可靠性,而且有利于产品的几何设计和影响加工效率的刀具选择。研究表明所提方法和算法是合理有效的。 相似文献
13.
居玲 《机械制造与自动化》2012,41(5):166-167,178
为了提高太阳能焊接机的焊接精度和焊接速度,提出了基于机器视觉在线检测太阳能电池片位置误差的方法。采用最小误差法对图像进行阈值分割,通过轮廓提取出电池片的轮廓;采用Hough变换直线检查的方法得到了电池片边缘及三线所在直线;计算出电池片的位置误差。实验结果验证了该方法的有效性。 相似文献
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针对铸件X射线图像获取困难、人工及传统识片方法效率低且漏判率高的问题,文中提出了一种基于深度学习的铸件缺陷检测方法。首先,采用Overlap切图(重叠切图)数据增广方法实现缺陷扩充,并基于简化Mosaic数据增广进一步提升图像的复杂度;然后,基于仅浏览一次(You Only Look Once, YOLO)的理念实现缺陷检测模型构建;最后,提出一种基于边界框抑制的测试图像缺陷检测方法,以子图迭代方式完成测试图像中的缺陷检测。实验结果表明,该方法能够有效实现多种铸件缺陷的自动检测,为铸件缺陷检测提供了基于深度学习的解决方案。 相似文献
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