Physics-based learning with channel attention for Fourier ptychographic microscopy

Fourier ptychographic microscopy (FPM) is a computational imaging technology for large field-of-view, high resolution and quantitative phase imaging. In FPM, low-resolution intensity images captured with angle-varying illumination are synthesized in Fourier space with phase retrieval approaches. However, system errors such as pupil aberration and light-emitting diode (LED) intensity error seriously affect the reconstruction performance. In this article, we propose a physics-based neural network with channel attention for FPM reconstruction. With the channel attention module, which is introduced into physics-based neural networks for the first time, the spatial distribution of LED intensity can be adaptively corrected. Besides, the channel attention module is used to synthesize different Zernike modes and recover the pupil function. Detailed simulations and experiments are carried out to validate the effectiveness and robustness of the proposed method. The results demonstrate that our method achieves better performance in high-resolution complex field reconstruction, LED intensity correction and pupil function recovery compared with the state-of-art methods. The combination with deep neural network structures like channel attention modules significantly enhance the performance of physics-based neural networks and will promote the application of FPM in practical use.