Dark2Light: multi-stage progressive learning model for low-light image enhancement.

Due to severe noise and extremely low illuminance, restoring from low-light images to normal-light images remains challenging. Unpredictable noise can tangle the weak signals, making it difficult for models to learn signals from low-light images, while simply restoring the illumination can lead to noise amplification. To address this dilemma, we propose a multi-stage model that can progressively restore normal-light images from low-light images, namely Dark2Light.

[Measurement of path transverse wind velocity profile using light forward scattering scintillation correlation method].

A new method for path transverse wind velocity survey was introduced by analyzing time lagged covariance function of different separation sub-apertures of Hartmann wavefront sensor. A theoretical formula was logically deduced for the light propagation path transverse wind velocity profile. According to the difference of path weighting function for different sub apertures spacing, how to select reasonable path weighting functions was analyzed.

[A CMOS vertically integrated device for monochromatic spectrum detection].

A vertically integrated sensor based on standard CMOS process, which can detect the wavelength of the monochromatic spectrum, was designed, manufactured and tested. It took the advantage of the two-layer structure of the device which can sense short wavelength and long wavelength illumination (among near UV, visible and near IR) simultaneously, then through these two different responses, the final device response showed monotonically increasing with the wavelength, and the wavelength can be known through this monotonicity. First we introduced the basic principle of the device, then the ideas in test device design were given.

[The analysis of the sampling modulation transfer function and the influence on the Gaussian spectra].

As the parameters of the photoelectric detector have important effects on the performance of the dispersive spectrometers, it is necessary to detail the discrete sampling process of the photoelectric detector array. In the present paper, the sampling model was setup, and the effects on the sampling results caused by the spatial frequency of the cosine signal, the width of the sampling pixel, and the initial phase of the sampling pixel position to the crest of the input cosine signal were discussed thoroughly in the frequency domain. By introducing the integral function, a general expression of the sampling modulation transfer function was given, and the concept and expression of the average sampling modulation transfer function was proposed.

[Stray light and bandpass correction in the spectral measurement for light emitting diodes].

The present paper introduces the stray light and bandpass correction methods for spectrometers. The line spread function of spectrometer is characterized by a He-Ne laser. Assuming that the spectrometer is a wavelength invariable system, the stray light distribution matrix is constructed by the derived line spread functions.

[Multispectral color sensor based on vertically stacked structure].

A novel multispectral color sensor based on vertically stacked structure is introduced. The advantages of this sensor include anti color aliasing, high spatial resolution, elimination of color interpolation and low-pass filter. Its basic principle lies on the silicon material's different of penetration depth of electromagnetic wave with different wavelength, i.