Optical Aberration Calibration and Correction of Photographic System Based on Wavefront Coding

Abstract

The image deconvolution technique can recover potential sharp images from blurred images affected by aberrations. Obtaining the point spread function (PSF) of the imaging system accurately is a prerequisite for robust deconvolution. In this paper, a computational imaging method based on wavefront coding is proposed to reconstruct the wavefront aberration of a photographic system. Firstly, a group of images affected by local aberration is obtained by applying wavefront coding on the optical system’s spectral plane. Then, the PSF is recovered accurately by pupil function synthesis, and finally, the aberration-affected images are recovered by image deconvolution. After aberration correction, the image’s coefficient of variation and mean relative deviation are improved by 60% and 30%, respectively, and the image can reach the limit of resolution of the sensor, as proved by the resolution test board. Meanwhile, the method’s robust anti-noise capability is confirmed through simulation experiments. Through the conversion of the complexity of optical design to a post-processing algorithm, this method offers an economical and efficient strategy for obtaining high-resolution and high-quality images using a simple large-field lens.

A Phase Recovery Technique Using the Genetic Algorithm for Aberration Correction in a Coherent Imaging System

“…With the development of the phase recovery algorithm, more and more researchers focus on improving the image quality of coherent imaging systems by reconstructing pupil function. In 2021, Yao et al [ 9 ], of the Zhejiang University, obtained the PSF (point diffusion function) of each sub-aperture of the system through wavefront coding, then reconstructed pupil function using a phase recovery algorithm, then obtained system PSF based on reconstructed pupil function, and then improved the image quality of the system through deconvolution. In 2022, Wang et al [ 10 ], of the Foshan University, improved the quality of reconstructed images by optimizing spectral function and pupil function based on a phase recovery strategy.…”

Extended Depth-of-Field Imaging Using Multi-Scale Convolutional Neural Network Wavefront Coding

“…Wavefront coding(WFC) is a depth-of-field(DOF) extension technology that integrates optical and digital image processing [1]. This system not only can achieve a large depthof-field extension but also can correct aberrations related to defocusing.…”

Method and Device of All-in-Focus Imaging with Overexposure Suppression in an Irregular Pipe

“…Although this method can be adapted to circular pipes of varying sizes by changing lenses, irregular pipes typically provide frequent and large radial depth-of-field (DoF) changes that make information acquisition prohibitively difficult and time-consuming. Imaging systems with expanded DoFs are helpful, and researchers have offered several related solutions (e.g., wavefront coding [ 12 , 13 ], special flat lensing [ 14 ], and light-field imaging [ 15 , 16 ]) that improve DoF handling at the expense of spatial resolution. However, these results are unsuitable for reliable defect detection.…”