High-speed image reconstruction for nonlinear structured illumination microscopy

By exploiting the nonlinear responses of fluorescent probes, the spatial resolution of structured illumination microscopy (SIM) can be further increased. However, the traditional reconstruction method of nonlinear structured illumination microscopy (NL-SIM) is very slow due to its complex process, which poses a significant challenge to display super resolution results in real-time. Here, we describe an efficient and robust SIM algorithm that enables rapid and accurate full-process SIM reconstruction. First, we present a fast illumination parameters estimation algorithm based on discrete Fourier transforms that result in a more simplified workflow than that of classical methods. Second, an accelerated NL-SIM reconstruction algorithm is developed by extending a high-speed reconstruction framework, joint space and frequency reconstruction (JSFR), to the NL-SIM. In particular, we provide the open-source MATLAB toolbox of our JSFR-NL-SIM algorithm. The entire image reconstruction process is completed in the milliseconds range, representing a significant time saving for the user.