Federico Alejandro, Kaufmann Guillermo H
Centro de Investigación y Desarrollo en Física, Institute Nacional de Tecnología Industrial, P.O. Box B1650WAB, B1650KNA San Martin, Argentina.
Appl Opt. 2003 Dec 10;42(35):7066-71. doi: 10.1364/ao.42.007066.
We evaluate the use of a smoothed space-frequency distribution (SSFD) to retrieve optical phase maps in digital speckle pattern interferometry (DSPI). The performance of this method is tested by use of computer-simulated DSPI fringes. Phase gradients are found along a pixel path from a single DSPI image, and the phase map is finally determined by integration. This technique does not need the application of a phase unwrapping algorithm or the introduction of carrier fringes in the interferometer. It is shown that a Wigner-Ville distribution with a smoothing Gaussian kernel gives more-accurate results than methods based on the continuous wavelet transform. We also discuss the influence of filtering on smoothing of the DSPI fringes and some additional limitations that emerge when this technique is applied. The performance of the SSFD method for processing experimental data is then illustrated.
我们评估了在数字散斑图案干涉测量法（DSPI）中使用平滑空间频率分布（SSFD）来获取光学相位图的情况。通过使用计算机模拟的DSPI条纹来测试该方法的性能。沿着单个DSPI图像中的像素路径找到相位梯度，最终通过积分确定相位图。该技术不需要应用相位解缠算法或在干涉仪中引入载波条纹。结果表明，具有平滑高斯核的维格纳-威利分布比基于连续小波变换的方法能给出更准确的结果。我们还讨论了滤波对DSPI条纹平滑的影响以及应用该技术时出现的一些其他限制。然后说明了SSFD方法处理实验数据的性能。
