Fourier single-pixel imaging (FSI) has attracted increased attention in recent years with the advantages of a wide spectrum range and low cost. FSI reconstructs a scene by directly measuring the Fourier coefficients with a single-pixel detector. However, the existing sampling method is difficult to balance the noise suppression and image details within a limited number of measurements. Here we propose a new sampling strategy for FSI to solve this problem. Both the generality of the spectral distribution of natural images in the Fourier domain and the uniqueness of the spectral distribution of the target images in the Fourier domain are considered in the proposed method. These two distributions are summed with certain weights to determine the importance of the Fourier coefficients. Then these coefficients are sampled in order of decreasing importance. Both the simulations and experiments demonstrate that the proposed method can capture more key Fourier coefficients and retain more details with lower noise. The proposed method provides an efficient way for Fourier coefficient acquisition.
For the modulation-based structured illumination microscopy system, how to obtain modulation distribution with an image has been a research hotspot. However, the existing frequency-domain single-frame algorithms (mainly including the Fourier transform method, wavelet method, etc.) suffer from different degrees of analytical error due to the loss of high-frequency information. Recently, a modulation-based spatial area phase-shifting method was proposed; it can obtain higher precision by retaining high-frequency information effectively. But for discontinuous (such as step) topography, it would be somewhat smooth. To solve the problem, we propose a high-order spatial phase shift algorithm that realizes robust modulation analysis of a discontinuous surface with a single-frame image. At the same time, this technique proposes a residual optimization strategy, so that it can be applied to the measurement of complex topography, especially discontinuous topography. Simulation and experimental results demonstrate that the proposed method can provide higher-precision measurement.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.