Micro-PIV三维测量图像处理及优化研究

Study of the Processing and Optimization of Micro-PIV-based Three-dimensional Measurement Images

Micro-PIV是一种重要的微尺度流动测速技术,可获得示踪颗粒速度和绘制流体速度场。在实验室已有显微测量技术基础上,发展了Micro-PIV三维测量图像处理技术,并对图像处理进行了优化和修正。颗粒图像中心二维坐标的精确性关键在于如何根据图像中心主要特征进行识别定位。荧光颗粒的三维识别是基于颗粒衍射图像随离焦量变化而变化,通过待测实验图像与数值模板的匹配实现Micro-PIV三维测量,数值图像的离焦量就是实验图像的离焦量。在分析实验图像和数值模板基础上分别对实验图像进行预处理和对数值模板进行修正,使得实验荧光颗粒图像与数值模板匹配效果更好。

Micro-PIV is an important micro-scale flow velocity measurement technology,capable of acquiring the speed of tracer particles and plotting a flow field of the fluid.On the basis of the currently available microscopic measurement technologies in the laboratory,the authors developed a Micro-PIV three-dimensional measurement image processing technology and conducted an optimization and corrected optimization of the image processing.The key to the precision of the two-dimensional coordinates of the particle image centers lies in the matter how to identify and locate the particles according to the main characteristics of the image centers.A three-dimensional identification of fluorescent particles is based on the diffraction images of the particles,which change with the defocus distance,and a Micro-PIV three-dimensional measurement is realized through a matching of the test images to be measured and the numerical template.The defocus distance of a numerical image is that of the test image.On the basis of an analysis of the test images and the numerical template,the test images were pretreated and the numerical template was corrected respectively,resulting in a better matching effectiveness of the test fluorescent particle images and the numerical template.