Jang Jae-Young, Yoo Hoon
Department of Optometry, Eulji University, 553, Sanseong-daero, Sujeong-gu, Seongnam-si, Gyonggi-do 13135, Korea.
Department of Electronics Engineering, Sangmyung University, 20 Hongjimoon-2gil, Jongno-gu, Seoul 03015, Korea.
Sensors (Basel). 2020 Sep 9;20(18):5137. doi: 10.3390/s20185137.
This paper describes an image enhancement method of computational reconstruction for 3-D images with multiple parallax image arrays in diffraction grating imaging. A 3-D imaging system via a diffraction grating provides a parallax image array (PIA) which is a set of perspective images of 3-D objects. The parallax images obtained from diffraction grating imaging are free from optical aberrations such as spherical and chromatic aberrations that are always involved in the 3-D imaging via a lens array. The diffraction grating imaging system for 3-D imaging also can be made at a lower cost system than a camera array system. However, the parallax images suffer from the speckle noise due to a coherent source; also, the noise degrades image quality in 3-D imaging. To remedy this problem, we propose a 3-D computational reconstruction method based on multiple parallax image arrays which are acquired by moving a diffraction grating axially. The proposed method consists of a spatial filtering process for each PIA and an overlapping process. Additionally, we provide theoretical analyses through geometric and wave optics. Optical experiments are conducted to evaluate our method. The experimental results indicate that the proposed method is superior to the existing method in 3-D imaging using a diffraction grating.
本文描述了一种用于衍射光栅成像中具有多个视差图像阵列的三维图像的计算重建图像增强方法。通过衍射光栅的三维成像系统提供视差图像阵列（PIA），它是三维物体的一组透视图像。从衍射光栅成像获得的视差图像没有诸如球面像差和色差等光学像差，而这些像差在通过透镜阵列的三维成像中总是存在的。用于三维成像的衍射光栅成像系统也可以制造成比相机阵列系统成本更低的系统。然而，视差图像会受到相干源产生的散斑噪声的影响；而且，这种噪声会降低三维成像中的图像质量。为了解决这个问题，我们提出了一种基于通过轴向移动衍射光栅获取的多个视差图像阵列的三维计算重建方法。所提出的方法包括对每个PIA的空间滤波过程和重叠过程。此外，我们通过几何光学和波动光学进行了理论分析。进行了光学实验以评估我们的方法。实验结果表明，在使用衍射光栅的三维成像中，所提出的方法优于现有方法。
