基于改进 Canny 算子的锂电池极片表面缺陷检测

针对目前锂电池极片表面存在低对比度微小缺陷难以检测的问题,提出了一种基于改进Canny算子的锂电池极片表面缺陷检测方法。首先,使用双边滤波改善高斯滤波在降噪时可能造成的图像边缘模糊问题,并在此基础上引入多尺度细节增强算法来增强低对比度图像;其次,基于Sobel算子的3×3梯度模板计算极片图像的梯度幅值和梯度方向;最后,基于最大熵和Otsu算法自动获取图像的高、低阈值,通过逻辑与运算对两种算法阈值分割后的检测结果进行边缘融合,并利用形态学闭运算和细化算法修复不连续边缘,得到最终检测边缘。实验结果表明,传统Canny算子和Otsu-Canny算法难以有效检测不同类型的暗斑、露箔和划痕缺陷,而本文算法对这些缺陷均取得了较好的检测效果,能够在突出目标缺陷区域的同时,有效减少同色度背景噪声,正确检测率达98%,具有一定实用价值。

Lithium battery electrode plate surface defect detection based on improved Canny operator

Aiming at the problem that it is difficult to detect the small defects with low contrast existing on the surface of lithium battery electrode plate, a new lithium battery electrode plate surface defect detection method based on improved Canny operator is proposed. Firstly, bilateral filtering is used to solve the image edge blur problem caused by Gaussian filtering when reducing noise, and on this basis, multi-scale detail enhancement algorithm is introduced to enhance the low contrast image. Secondly, the 3×3 gradient template of Sobel operator is used to calculate the gradient amplitude and gradient direction of electrode plate images. Finally, based on the maximum entropy and Otsu algorithm, the high and low thresholds of the image are automatically obtained. The detection results of the two algorithms after threshold segmentation are edge-fused with logic and operation, and the discontinuous edges are repaired with morphological closed operation and thinning algorithm to obtain the final detection edge. The experiment results show that the traditional Canny operator and Otsu-Canny algorithm are difficult to effectively detect the defects, including different types of dark spots, exposed foil and scratches. However, the algorithm in this paper can achieve good detection results for these defects, which can effectively reduce the same color background noise, while highlight the target defect area. The correct detection rate reaches 98% , the propose algorithm has a certain practical value.