Wavelet-based processing of ECT images for inspection of printed circuit board
Wavelet-based processing of ECT images for inspection of printed circuit board
复制标题
用于印刷电路板检查的 ECT 图像的小波处理
DOI：
10.1109/20.951308
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发表时间：
2001
影响因子：
2.1
通讯作者：
M. Iwahara
中科院分区：
文献类型：
--
作者：
T. Taniguchi;D. Kacprzak;S. Yamada;M. Iwahara
本文提出了一种基于小波变换的图像处理技术，它分析涡流检测（ECT）探头扫描印刷电路板（PCB）的图像，并自动检测缺陷的存在和位置。首先，通过两种类型的小波滤波去除探头输出中包含的不期望的分量。然后，从参考和测试的PCB的获得的两个图像的比较进行提取的信号，由于缺陷。考虑到探头的扫描方向是沿着水平方向，本文仅在水平方向使用一维小波。此外，还提出了以原始信号与处理后信号之差的平方范数为准则，尽可能保持缺陷峰的波形。最后，通过对典型PCB的应用实例，说明了该方法的有效性和存在的问题.
This paper presents a wavelet-based image processing technique, which analyzes eddy-current testing (ECT) images derived by scanning printed circuit boards (PCB's) with an ECT probe and automatically detects the existence and location of the defect. First, the undesired components contained in probe output are removed through two types of wavelet filtering. Then the comparison of two images obtained from reference and tested PCB's are carried out to extract the signal due to the defect. In this paper, one-dimensional (1-D) wavelet is used only in the horizontal direction considering that the scanning of the probe is along that direction. In addition, the square norm of difference between original and processed signal is proposed as a criterion to keep the waveform of the defect peak as possible. The application examples of sample PCB's reveal the effectiveness and problems of the given approach.