标题： 背景定向阴影法（BOS）的点跟踪方法 显示英文标题

标题： Dot-Tracking Methodology for Background Oriented Schlieren (BOS)

摘要： 我们提出了一种用于处理背景定向阴影（BOS）图像的点跟踪方法。 该方法相比传统的互相关算法显著提高了准确性、精度和空间分辨率。 我们的方法利用了关于点图案的先验信息，例如点的位置、大小和数量，即使在高点密度（20个点/32x32像素）的情况下也能实现接近100%的产出率，并且对图像噪声具有鲁棒性。 我们还提出了对跟踪过程中的位移估计步骤的改进，特别是在嘈杂图像中，使用“相关校正”，即结合跟踪方法的空间分辨率优势和相关方法的平滑特性，以提高整体测量过程的动态范围。 我们通过使用光线追踪模拟生成的浮力驱动湍流的合成BOS图像，以及收敛-发散喷管出口平面流动的实验图像来评估该方法的性能。 显示英文摘要

摘要： We propose a dot-tracking methodology for processing Background Oriented Schlieren (BOS) images. The method significantly improves the accuracy, precision and spatial resolution compared to conventional cross-correlation algorithms. Our methodology utilizes the prior information about the dot pattern such as the location, size and number of dots to provide near 100% yield even for high dot densities (20 dots/32x32 pix.) and is robust to image noise. We also propose an improvement to the displacement estimation step in the tracking process, especially for noisy images, using a "correlation correction", whereby we combine the spatial resolution benefit of the tracking method and the smoothing property of the correlation method to increase the dynamic range of the overall measurement process. We evaluate the performance of the method with synthetic BOS images of buoyancy driven turbulence rendered using ray tracing simulations, and experimental images of flow in th exit plane of a converging-diverging nozzle.