Guoqiang Ni

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Traditional image enhancement algorithm based on the Retinex theory has some limitations due to its hypothesis that the incident light is changing smoothly. In addition, the algorithm introduces color distortion and appears a halo phenomenon during the strong contrast between the light and dark when it is processing the three components of the incident(More)
Medical images, such as magnetic resonance (MR) images are crucial in clinical diagnosis. However, MR images always suffer from poor contrast due to imaging techniques. Therefore, an image enhancement approach based on multi-scale Retinex is presented in this paper. A set of MR images which show coronal slices are employed as testing samples. The(More)
A new design of light source arrangements for indoor visible light communication is proposed in this paper to obtain uniform lighting conditions and stable communication performance. The models of illuminance and received signal to noise ratio are established in a room. The room size is 5 m×5 m×3 m. A 2-factor of signal to noise ratio(More)
We propose a scheme for designing a new optical receiving system that can reduce the received-energy spot size via integration of a compound parabolic concentrator with a hemispherical lens. SolidWorks is used to model the receiving system, while TracePro is employed for simulations. The field of view is set to 30° and the radius of the compound parabolic(More)
To efficiently recover blurred image degraded by vibration, this paper proposes a way to simulate vibration blurred images and measures direction and amplitude of vibration and gets movement parameters of vibration and point spread function of blurred image. The simulation method of time part image superposition is given according to degradation model of(More)
Abstract: The subpixel dynamic imaging technique of a beam splitter is one of the most effective super-resolution imaging methods. Aiming to create a linear time delay integration charge coupled device (TDI–CCD) subpixel imaging system based on the optical assembly method, its modulation transfer function (MTF) is analyzed based on the spatial over-sampling(More)
Signal waveform modulation is a novel multi-level method and can achieve higher recording density than the amplitude multi-level modulation. Affected by multi-level modulation, the tracking error signal generated by the conventional differential phase detection (DPD) method deteriorates in the signal waveform modulation multi-level (SWML) disc. In the(More)