High-Accuracy Correction of a Microlens Array for Plenoptic Imaging Sensors

Abstract

Microlens array (MLA) errors in plenoptic cameras can cause the confusion or mismatching of 4D spatio-angular information in the image space, significantly affecting the accuracy and efficiency of target reconstruction. In this paper, we present a high-accuracy correction method for light fields distorted by MLA errors. Subpixel feature points are extracted from the microlens subimages of a raw image to obtain correction matrices and perform registration of the corresponding subimages at a subpixel level. The proposed method is applied for correcting MLA errors of two different categories in light-field images, namely form errors and orientation errors. Experimental results show that the proposed method can rectify the geometric and intensity distortions of raw images accurately and improve the quality of light-field refocusing. Qualitative and quantitative comparisons between images before and after correction verify the performance of our method in terms of accuracy, stability, and adaptability.

Depth-of-Field-Extended Plenoptic Camera Based on Tunable Multi-Focus Liquid-Crystal Microlens Array

“…Compared to the standard plenoptic camera, the focused plenoptic camera can achieve a much higher spatial resolution of the rendered images but still with a limited depth of field (DOF). Nowadays, there are three kinds of plenoptic cameras that attract a wide range of research interest: A plenoptic camera based on a microlens array (MLA) [1][2][3][4][11][12][13], a plenoptic camera based on a camera array [14], and a plenoptic camera based on a coded mask [15]. Specifically, among the three main designs, the plenoptic camera based on the MLA has a very promising development prospect due to its small size, low cost, and light-field acquisition in a single photographic exposure.…”