Extended light-source-based lensless microscopy using constrained and regularized reconstruction

Lensless microscopy is a simple, portable, and cost-effective method of microscopy. It has been extensively investigated with coherent light sources such as laser setups or partially coherent light sources such as an LED filtered with a pinhole aperture. The coherence of light has a direct influence on the resolution of the reconstructed object. This paper presents lensless microscopy with a spatially extended light source (white LED flashlight without any subsequent engineering). A reconstruction method based on constrained and regularized optimization is presented. The resolution reduced due to decreased coherence is gained by the presented method of object estimation.