图像处理在DIC分析中的应用
用于二维或三维数字图像相关性测试的采集图像有时可能存在过暗、噪点过多、模糊或混叠等问题。我们时常被问及：使用Photoshop等软件处理这些图像是否能解决上述问题？
简而言之，此类处理毫无益处。图像信息在从相机传输至电脑的瞬间即已固定；后续调整虽可改变图像外观，却无法提升相关性分析结果，甚至可能造成损害。
关于亮度问题，Vic-2D和Vic-3D会自动进行图像标准化处理；人为增加数字增益不仅无益，还可能引入量化误差。其他处理操作（如尺寸调整、旋转、滤波）可能引发问题，因为Vic-2D和Vic-3D的插值算法是为模拟已知物理相机特性而精心设计的。任何软后处理都可能产生其他伪影。
若图像过暗导致难以绘制AOI或查看结果叠加层，可使用工具栏中的直方图控制项调整图像外观。此操作不影响相关性计算，但能显著提升图像可视性与绘图便利性。
以下为英文原文：
Processing Images for DIC Analysis
Sometimes, images acquired for use in 2D or 3D digital image correlation tests can be too dark; noisy; blurry; or aliased. From time to time we are asked whether it would be beneficial to process these images in software such as Photoshop to fix these issues.
In short, this is never beneficial. The information content of the image was set in stone as soon as it was sent from the camera to the PC; further adjustments can change the look of the image, but will not improve your correlation results and may possibly hurt them.
In the case of brightness, Vic-2D and Vic-3D will normalize the image internally; adding digital gain to the image will provide no benefit and may introduce quantization errors. Other processing (resizing, rotation, filtering) may cause problems because the interpolation algorithms in Vic-2D and Vic-3D are carefully designed to approximate known physical camera behaviors. Any soft postprocessing may create other artifacts.
If an image is too dark to see well for the purposes of drawing an AOI or viewing result overlays, you can use the Histogram control in the toolbar to adjust the look of the image. This does not affect the correlation, but can make the image much easier to see and draw on.