Point spread function degradation model of a polarization imaging system for wide-field subwavelength nanoparticles

Zhang

et al. 2021

IEEE Access

Self Cite

Polarization modulation imaging technology plays an important role in microscopic superresolution imaging. However, the specimen medium contains retardancy, while charge-coupled devices may provide discrete under-sampling, and the coupled wavefronts consisting of the polarization state of the light and the anisotropic distribution of the specimen can lead to vectorial phase fitting degradation. Considering that the point spread function (PSF) of the main degradation parts can be regarded as an asymmetric generalized Gaussian distribution with uncertain parameters, an adaptive image reconstruction method is proposed based on variable exponential function regularization. The proposed method concentrates on the diversity of the PSF and uses a variable exponent regularization to improve flexibility of the kernel. Moreover, it can balance image edge preservation and provide staircase artifact suppression, which reduces the over-and under-reconstruction of the microscopic images effectively. By optimizing the Split-Bregman algorithm, we create an efficient method that minimizes the iterative loss function under the premise of achieving high estimation accuracy. Compared with other methods, the experimental results reveal better effectiveness and robustness of the proposed method, with improvements of 18% in the peak signal-to-noise ratio, 21% in the structural similarity index measurement, and 337% in the mean structural similarity index measurement.

Image Reconstruction Using Variable Exponential Function Regularization for Wide-Field Polarization Modulation Imaging

Zhang

et al. 2021

IEEE Access

Self Cite

Point spread function degradation model of a polarization imaging system for wide-field subwavelength nanoparticles: publisher’s note

Hua

et al. 2020

Appl. Opt.

Three-dimensional reconstruction using variable exponential function regularization for wide-field polarization modulation imaging of surface texture of particles

Mao

et al. 2021

Opt. Lett.

Shapes from the diffuse polarization method effectively realize the three-dimensional (3D) reconstruction of the object surface by using the polarization information of the diffuse reflection light. However, due to the nonconvexity of the particle surface, the reconstruction often falls into a local optimal solution. Indeed, the depth image obtained by the scanning electron microscope has serious stripe noise, which distorts the surface texture of the particle. In this Letter, a variable exponential function regularization method is proposed to realize 3D reconstruction for the nonconvexity of the surface and inclination of the particles. We focus on the gradient unintegrability caused by the skew and surface undulation of the specimen. An adaptive 3D reconstruction method is proposed based on variable exponential function regularization to fit the surface function of the particle. Experimental results of finite-difference time-domain simulations and actual imaging demonstrate the effectiveness of the method.