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The dynamic three-dimensional(3D) surface imaging technology based on fringe projection was summarized and the characteristics of typical strategies were analyzed. Firstly, the basic principle of the technique was introduced, including the basic structure of the system, the principle of 3D surface imaging, and the two typical phase extraction methods, phase shifting method and Fourier transform method. Secondly, the dynamic imaging scheme including high speed projection scheme and dynamic 3D surface imaging method using relatively low speed camera was introduced. Thirdly, the absolute phase acquisition methods in dynamic 3D image were introduced, mainly analog and digital coding and area statistical coding, were introduced. Finally, the methods of accurate dynamic phase measurement were introduced.

Network monitoring system is handled by the automatic collection of web content, sensitive word filtering, intelligent clustering classification, topic detection, thematic focus, statistical analysis, a number of links to realize the need of the supervision and management of network public opinion, and ultimately the formation of public opinion, special reports, analysis reports, statistical reports, decision-making and management have complete control of public opinion, the dynamic, to make the right to guide public opinion, provide an analytical basis. The current monitoring system has some drawbacks such as small monitoring scope and less real-time. Coal mine safety monitoring and early warning systems are designed based on wireless sensor network in this paper. This system realized channel access to S MAC protocol, and transmitted environment information collected such as CO, CH4, temperature, humidity and my roof pressure, etc. to the monitoring station and realized real-time monitoring of the mine working environment parameters. Modeling simulation is performed on the wireless network structure by applying OPNET software, and the results show that in the wireless transmission condition, 20 nodes sent 1000 data packets, more than fifty of which are received. Wireless transmission network performs well.

The effect of system parameters on the reconstructed image quality in in-line digital holographic microscopy was studied.Firstly the spatial frequency of object wave was computed.Under the assumption of perfect imaging,the spatial frequency of object wave in the image space was completely determined by the frequency of the surface structure of the measured specimen and the magnification of the imaging system.Then,a suitable magnification must be designed so that the spatial frequency of object wave in the image space could satisfy the sampling capacity,based on the analysis that all the spatial frequency components of object wave should arrive at the recording plane and be effectively recorded in order to acquire the reconstructed image with high quality.And the recording distance affects on the object size which can be effectively recorded.When the magnification was the same,the size became larger with the decrease of the recording distance.Both the simulation and optical experiments validate the correctness of the proposed analysis.

To generate digital holograms with a large viewing angle,a digital holographic technique based on filter imaging is proposed.Using the off-axis image plane holography,a low-pass filter is placed at the spatial frequency plane of the 4F coherent imaging system,in order to make the object wave(satisfied CCD resolution ratio) interfere with the reference wave,and the loss-pass filter and imaging areas are controlled to record the sub-holograms for different spectra in turn.In digital holographic reconstruction,all sub-holograms are carried on numerical Fourier transform,and the corresponding spectra are reconstructed which are also stitched to form a whole spectrum of object wave.Then,a large viewing angle reconstruction image can be obtained by digital holography.The proposed technique is applied to the three-dimensional profile measurement of a sewing needle,and the experimental results prove the accuracy of this technique.

In this letter a new skeletonization algorithm is proposed. It combines techniques of fast construction of Euclidean Distance Maps(EDMs), ridge extraction, Hit-or-Miss Transformation(HMT) of structuring elements and the set operators. It first produces the EDM image with no more than 4 passes through an image of any kinds, and then the ridge image is extracted by applying a turn-on scheme and performing a rain-fall elimination to accelerate the processing. The one-pixel wide skeleton is finally acquired by carrying out the HMTs of two structure elements and the SUBTRACT and OR operations. Experimental results obtained by practical applications are also presented.