中国激光, 2018, 45 (1): 0104004, 网络出版: 2018-01-24
激光超声可视化图像处理研究 下载: 870次
Research on Laser Ultrasonic Visual Image Processing
摘要
在激光超声可视化成像过程中, 外界噪声、入射波等干扰导致了图像质量下降, 造成了缺陷识别能力不足。利用局部统计滤波算法降低散斑噪声干扰, 通过考察平均梯度和熵值以评估降噪效果。利用二阶微分算子对降噪后的图像进行图像增强, 比较了不同微分算子的图像增强效果。提出利用罚函数方法抑制入射波对缺陷散射波的干扰, 通过权重因子和正则化因子的变化考察了峰值信噪比和结构相似性的变化趋势, 并与相邻波相减抑制入射波方法进行了对比。结果表明, 通过图像处理方法可以改善激光超声可视化图像质量, 突显缺陷信息。
Abstract
In the process of laser ultrasonic visualization, the external noise and incident wave lead to lower image quality and defect identification capability. In this paper, local statistic filtering is used to reduce the interference of speckle noise, and average gradient and entropy are investigated in order to evaluate denoising results. Two-order differential operator is applied to the enhancement of denoised image, and the image enhancement effects with different differential operators are compared. The penalty function is used to restrain the interference of incident wave on defect scattering wave. The variation trend of peak signal-to-noise ratio and structural similarity are investigated by weighting factor and regularization coefficient, and the method is compared with the method of suppressing incident wave by subtraction of adjacent waves. The results show that the laser ultrasonic visual image quality can be improved by image processing method, and the defect information can be highlighted.
朱洪玲, 刘畅, 张博, 蔡桂喜. 激光超声可视化图像处理研究[J]. 中国激光, 2018, 45(1): 0104004. Zhu Hongling, Liu Chang, Zhang Bo, Cai Guixi. Research on Laser Ultrasonic Visual Image Processing[J]. Chinese Journal of Lasers, 2018, 45(1): 0104004.