一种基于图像处理的熔体润湿角计算方法

A Method for Calculating Melt Wetting Angle Based on Image Processing

考察熔体与界面之间的润湿性,对表征界面相互作用及分析材料工艺特性等具有重要意义。针对现有润湿角计算方法自动化程度不足、计算较大润湿角不够精确等局限,基于Sobel算子、矩形定位、Harris角点检测等图像处理算法和手段,提出一种熔体润湿角的全自动计算方法。Sobel算子实现了基座自动定位;应用矩形定位,采用外接矩形法、内接矩形法相结合自动定位样品,消除了主观操作所引入的误差;应用Harris角点检测方法,对非样品轮廓点进行了处理,得到了完整的样品轮廓。为了进一步提高准确性,将轮廓拆分为左右半边,并基于迭代重加权最小二乘法分别用椭圆拟合计算接触角。基于座滴法测量系统对铜和玻璃样品的润湿角进行测量,对轮廓拟合及润湿角计算误差进行统计分析,得出干扰对轮廓拟合的影响,开展精度计算,表明该方法能够在较大的温度区间内准确计算润湿角,并且在多次重复实验中标准偏差不高于0.7°,提高了轮廓拟合的精度;计算方法具有良好的可复现性。

Investigating the wettability between the melt and the interface is of great significance for characterizing the interfacial interaction and analyzing the technological properties of materials.Aiming at the limitations of the existing wetting angle calculation methods and measures,such as insufficient automation and inaccurate calculation of larger wetting angles,a fully automatic calculation method based on image processing algorithms such as Sobel operator,rectangle positioning,and Harris corner detection was proposed.The Sobel operator realized the automatic positioning of the base;by applying the rectangle positioning,the circumscribed rectangle method and the inscribed rectangle method were combined to realize the automatic positioning of the sample,which eliminated the error introduced by the subjective operation;by applying the Harris corner detection method,the non-sample contour points were processed,and a complete Sample contour was obtained.To further improved the accuracy,the contour into left and right halves were split,and the contact angle with ellipse fitting based on the iterative reweighted least squares method was calculated.The wetting angles of copper and glass samples were measured based on the sessile drop measurement system,the error of contour fitting and wetting angle calculation was statistically analyzed,the influence of the interference on the contour fitting was obtained,and the accuracy calculation was carried out,showing that the method can accurately calculate the wetting angles in a large temperature range,and the standard deviation was not higher than 0.7°in repeated experiments,which improves the accuracy of the contour fitting;such a calculation method is with a good reproducibility.