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With the development of economy, electronic products are playing an increasingly important role. People often need to stare at electronic screens to use electronic products. It can be effective in correcting vision by glasses or surgery for patients with ametropia. But these methods don't work for patients with high-order aberrations. In this work, a method of digital image processing is proposed for these patients. With wavefront aberrations of patient eyes obtained, source images can be pre-compensated to counteract the wavefront aberrations so that the patients can observe the clear images directly. In order to solve the contrast problem caused by the method, an algorithm based on a method of single defogging and Contrast-limited adaptive histogram equalization with subsequent processing is proposed. The algorithm is compared with some traditional methods qualitatively and quantitatively.

A terahertz (THz) imaging enhancement approach is presented by using multi-features of images. First, a set of THz images are reconstructed from a single data collection using THz time-domain spectroscopy system by selecting different features. Second, the THz beam model is considered to improve image resolution, which is realised via a Wiener de-convolution operation. Third, an approach to suppress the noise and enhance image feature is adopted to achieve a better image quality. Finally, three high-quality images are selected from the new image set as red, green, and blue channels, respectively, to form a pseudo-colour image. The experimental results suggest that the pseudo-colour images show multiple features of the sample and achieve a better image quality.

In phase measuring deflectometry (PMD), the existence of parasitic reflections at the rear surface of transparent objects will lead to ‘ghosted’ fringe patterns, which results in phase error. Accurately extracting the phase from the 'ghosted' fringe patterns is considered as one of the main problems in PMD. Existing phase extraction methods still remain some drawbacks such as high cost of experiment equipment, the existence of ill-conditioned areas and difficulty in setting up a suitable threshold. In this paper, the envelope curve algorithm based on multi-frequency approach is proposed to eliminate parasitic reflections. The parasitic reflections were eliminated successfully. The PV and the RMS of the front phase error are 0.1085 rad and 0.0072 rad, and those of the rear phase error are 0.1345 rad and 0.0081 rad respectively in the simulation. Experiments also proved the effectiveness of the proposed algorithm. What’s more, the phase information of both the front and the rear surfaces can be attained simultaneously. The proposed algorithm could eliminate parasitic reflections successfully without destroying the tested object or special equipment. Factors which may influence the performance of this algorithm are discussed, and results showed that the proposed method is especially suitable for thick transparent object. Keywords: Parasitic reflections, Multi-frequency approach, Phase measuring deflectometry, Fringe analysis, Fringe demodulation

On the base of MR and frequency sweeping data of TD-SCDMA, the network structure of TD-LTE after upgrading directly is analyzed, the problematic base stations are found and the solution aiming at strong interferences is proposed, the pre-planning of TD-LTE is illustrated in detail.