Image windowing mitigates edge effects in Differential Dynamic Microscopy
Image windowing mitigates edge effects in Differential Dynamic Microscopy
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DOI：
10.1140/epje/i2017-11587-3
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发表时间：
2017-11-09
影响因子：
1.8
通讯作者：
Cerbino, Roberto
中科院分区：
文献类型：
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作者：
Giavazzi, Fabio;Edera, Paolo;Cerbino, Roberto
差分动态显微镜(DDM)分析传统的真实空间显微镜图像，通过将序列中的每一幅图像分解成傅立叶模式，并评估其时间相关性，以类似于光散射的方式提取关于样品动力学的信息。DDM已在许多软物质和胶体体系中得到应用。然而，观察到的物体移出显微镜捕获的视场，与采集到的图像的边缘相交，可能会在后续分析中引入虚假的但显著的误差。这里，我们展示了在图像进入标准DDM分析之前，对序列中图像应用空间窗滤波可以大大减少这些伪影。此外，加窗可以显著增加DDM探测的波矢量的可及范围，并且可能进一步产生意想不到的信息，例如胶体悬浮液的尺寸多分散性。
Differential Dynamic Microscopy (DDM) analyzes traditional real-space microscope images to extract information on sample dynamics in a way akin to light scattering, by decomposing each image in a sequence into Fourier modes, and evaluating their time correlation properties. DDM has been applied in a number of soft-matter and colloidal systems. However, objects observed to move out of the microscope's captured field of view, intersecting the edges of the acquired images, can introduce spurious but significant errors in the subsequent analysis. Here we show that application of a spatial windowing filter to images in a sequence before they enter the standard DDM analysis can reduce these artifacts substantially. Moreover, windowing can increase significantly the accessible range of wave vectors probed by DDM, and may further yield unexpected information, such as the size polydispersity of a colloidal suspension.