Optical flow estimation based on the structure–texture image decomposition

Optical flow approaches for motion estimation calculate vector fields which determine the apparent velocities of objects in time-varying image sequences. Image motion estimation is a fundamental issue in low-level vision and is used in many applications in image sequence processing, such as robot navigation, object tracking, image coding and structure reconstruction. The accuracy of optical flow estimation algorithms has been improving steadily as evidenced by results on the Middlebury optical flow benchmark. Actually, several methods are used to estimate the optical flow, but a good compromise between computational cost and accuracy is hard to achieve. This work presents a combined local–global total variation approach with structure–texture image decomposition. The combination is used to control the propagation phenomena and to gain robustness against illumination changes, influence of noise on the results and sensitivity to outliers. The resulted method is able to compute larger displacements in a reasonable time.     

Steganography based on parameters’ disturbance of spatial image transform

In the research of state-of-the-art steganography algorithms,most of image sources were natural images in laboratory environment.However,with the rapid development of image process tools and applications,images after image processing were widely used in real world.How to use image process to improve steganography has not been systematically studied.Taking spatial image transform for consideration,a parameters’ disturbance model was presented,which could hide the noise taken by steganography in the pixel fluctuation due to the disturbance.Meanwhile,it would introduce cover source mismatch for a steganalyzer.The experimental results show that,compared with using traditional image database,it can significantly enhance the security of steganography algorithms and accommodative to the real world situation.     

Handover management based on user’s mobility specification

Considering the highly dynamic nature of wireless networks, the major challenge in this environment is the provision of QoS guarantees that different applications demand. Recent research is interested in advance resource reservation to provide the necessary QoS to the mobile terminals. Another way to obtain a better use of the resources in this environment is to determine the future locations of the mobile terminal. This paper describes a user’s mobility profile management based approach for advance resource reservation in wireless networks; it is based on theNsis signaling. This reservation is based on an objectMspec (Mobility Specification) which determines the future location of the mobile terminal. The mspec object is a part of a user’s mobility profile; this last is determined by the mobile terminal. Another applicability of our user’s mobility profile is in the 4G wireless systems, in this case; the mobile terminal supports various access technologies and the user’s mobility profile is used to adapt the vertical and the diagonal handover to the user’s needs.     

Dark satellite image enhancement using knee transfer function and gamma correction based on DWT–SVD

In this paper, an improved and simple approach for enhancement of dark and low contrast satellite image based on knee function and gamma correction using discrete wavelet transform with singular value decomposition (DWT–SVD) has been proposed for quality enhancement of feature. In addition, this method can also process the high resolution dark or very low contrast images, and offers best enhanced result using tuning parameter of Gamma. The technique decomposes the input image into four frequency subbands by using DWT and estimates the singular value matrix of the low–low subband image, and then compute the knee transfer function using gamma correction for further improvement of the LL component. Afterward, processed LL band image undergoes IDWT together with the unprocessed LH, HL, and HH subbands to generate an appropriate enhanced image. Although, various histogram equalization approaches has been proposed in the literature, they tend to degrade the overall image quality by exhibiting saturation artifacts in both low- and high-intensity regions. The proposed algorithm overcomes this problem using knee function and gamma correction. The experimental results show that the proposed algorithm enhances the overall contrast and visibility of local details better than the existing techniques.     

Theoretical-game estimate of radiosystem’s efficiency based on entropy approach

Theoretical-game synthesis of radio communications system in a conflict situation of interaction between radio communications system (RCS) and radio masking system (RMS) operators taking into consideration information limitations that are imposed on differential entropies of players’ mixed strategies.     

Systems of discrete composite frequency signals based on Gold’s sequences

Regular rules of constructing various systems of discrete composite frequency (DCF) signals have been proposed. Optimal systems of discrete frequency (DF) signals were chosen as a basis. In this case the extension of signal base is performed by the binary phase-shift keyed (BPS) signals coded by the Gold sequences. It was found out that the constructed systems of composite DCF-BPS signals possessed a number of essentially attractive properties.     

Algorithm for scenario benefit route planning based on user’s requests

Most of the existing research for point of interest route planning only consider the static properties of POI,however,the congestion of the hot spots and users’ discontent may greatly reduce the travel quality.In order to increase the tourists’ satisfaction,the dynamic attributes of POI was considered and a route planning algorithm based on user’s requests was proposed.Firstly,Markov-GM(1,1) forecasting algorithm was designed to predict the number of people in each scenic spot.Markov-GM(1,1) could make the average predication error 12.2% lower than the GM(1,1) algorithm by introducing the predication residual.And then,the forward refinement (FR) algorithm was designed which could avoid visiting the unnecessary place and satisfy user’s requests as well.The average solving time of forward refinement algorithm was 9.4% lower than TMT algorithm under the same amount of user’s requests.Finally,based on the factors such as spot popularity,KL divergence of time,visiting order and distance et al,the scenic route profit planning algorithm which could make the number of Rank 1-5 spots 34.8% higher than Time_Based algorithm and 47.3% higher than Rand_GA algorithm.     

Social network information diffusion model based on user’s influence and interesting

A new non-topological information diffusion model of social network was proposed,called non-topological influence-interest diffusion model (NT-II).Representation learning was exploited to construct two hidden spaces for NT-II,called the user-influence space and the user-interest space,each user and each propagation item was mapped into a vector in space.The model predicted the probability of a user receiving a propagated item,considering not only the degree of influence from other users,but also the user's preference for propagated item.The experimental results show that the model can simulate the propagation process and predict the propagation results more accurately.     

New Quadrotor Helicopter’s communication and control device based on BASYS3

商业化四轴飞行器上的遥控器功能单一,没有DIY 的能力,无法自行编写代码,不利于飞控新功能的开发。利用BASYS3作为主控芯片自行设计了新的遥控器,采用 433 模块进行无线通讯,与飞控板进行有效信息交互;实现了除商用摇杆控制功能以外,还具备语音控制四轴飞行器的功能。与此同时,遥控器还可以实现同时与定高、定点、航拍等相结合的功能,实现四轴飞行器的全面稳定控制,为四轴飞行器后期的开发利用提供了进一步的参考。     

Caching strategy based on node’s importance to community in information-centric networks

In-network caching is one of the most important features of ICN (information-centric networks).A caching strategy based on node’s importance to community was proposed to make content objects cached more reasonable in temporal and spatial distribution.Within each community,the strategy not only caches content objects in those nodes where users are easy to access the content,but also makes different popularity of content objects more reasonable in temporal distribution.The CSNIC strategy was implemented under a variety of experimental conditions,and compare it with the previous strategies CEE-LRU,Betw-LFU and Opportunistic.The simulation results show that the strategy can yield a significant performance improvement,such as,cache hit ratio,hop reduction ratio,content diversity ratio and number of replacement.Furthermore,the additional overhead of CSNIC is small.     

Design for secure two-party computation protocol based on ElGamal variant’s homomorphic

ElGamal homomorphic characteristics were analyzed.In order to meet the need of protocol design,ElGamal variant was designed,which satisfies additive homomorphism and constant multiplication homomorphism.A homomorphism calculate protocol of linear equation passed by two private point based on the ElGamal variant was also proposed,then the correctness,security and the complexity of computation and communication of the protocol were analyzed to extend the application of thinking to secure two-party line segments intersection scheme.Compared with the similar protocol of solving the geometric problem,a kind of secure two-party computation protocol based on homomorphic encryption system without using the oblivious transfer protocol and the millionaires protocol was put forward,which holds higher efficiency and a lower burden of communication.     

Bidirectional authentication key agreement protocol supporting identity’s privacy preservation based on RLWE

In order to solve the problem of identity privacy preservation between two participants involved when implementing authenticated key agreement protocol,a bidirectional authenticated key agreement protocol against quantum attack based on C commitment scheme was proposed.Through the design of C commitment function,the real identity information of two participants involved was hidden.Based on RLWE difficult problem,under the premise to ensure identity anonymity,this protocol not only completed two-way identity authentication,but also ensured the integrity of the transmitted message,furthermore,the shared session key was negotiated.After been analyzed,in terms of protocol’s execution efficiency,only two rounds of message transmission were needed to complete anonymous two-way authentication and key agreement in the proposed scheme.Compared with Ding’s protocol,the length of public key was reduced by nearly 50%.With regard to security,the protocol could resist forgery,replay,key-copy,and man-in-the-middle attacks.It is proved that the proposed protocol satisfies the provable security under the eCK model.At the same time,the protocol is based on the RLWE problem of lattices,and can resist quantum computing attacks.     

Distributed polar-coded OFDM based on Plotkin’s construction for half duplex wireless communication

A Plotkin-based polar-coded orthogonal frequency division multiplexing (P-PC-OFDM) scheme is proposed and its bit error rate (BER) performance over additive white gaussian noise (AWGN), frequency selective Rayleigh, Rician and Nakagami-m fading channels has been evaluated. The considered Plotkin’s construction possesses a parallel split in its structure, which motivated us to extend the proposed P-PC-OFDM scheme in a coded cooperative scenario. As the relay’s effective collaboration has always been pivotal in the design of cooperative communication therefore, an efficient selection criterion for choosing the information bits has been inculcated at the relay node. To assess the BER performance of the proposed cooperative scheme, we have also upgraded conventional polar-coded cooperative scheme in the context of OFDM as an appropriate bench marker. The Monte Carlo simulated results revealed that the proposed Plotkin-based polar-coded cooperative OFDM scheme convincingly outperforms the conventional polar-coded cooperative OFDM scheme by 0.5 ~ 0.6 dBs over AWGN channel. This prominent gain in BER performance is made possible due to the bit-selection criteria and the joint successive cancellation decoding adopted at the relay and the destination nodes, respectively. Furthermore, the proposed coded cooperative schemes outperform their corresponding non-cooperative schemes by a gain of 1 dB under an identical condition.     

Fake modern Chinese painting identification based on spectral–spatial feature fusion on hyperspectral image

Chinese painting is famous and valuable for special painting materials, skills and final art effects used, yet this has resulted in many fake paintings being produced. Those fake paintings were normally made by using modern high resolution scanning and printing technology, thus it is very hard to identify the fake ones by human vision. To address this challenging problem, in this paper, a hyperspectral image based features fusion method is proposed. Firstly, we scan Chinese paintings using a visual band hyperspectral camera with the spectral frequency ranging from 400 to 900 nm. Then, the spectral and spatial features are extracted respectively by using the principal component analysis and a convolution neural network. Finally, we fuse these two kinds of features and input the feature set into a support vector machines for classification. All samples of real and fake paintings are obtained from local Chinese painting organization. The experimental result shows the effectiveness of the proposed method with an accuracy achieved of 84.6 %, which is significantly higher than other approaches where only spectral or spatial feature is used.     

Visual saliency’s modulatory effect on just noticeable distortion profile and its application in image watermarking

Perceptual watermarking should take full advantage of the results from human visual system (HVS) studies. Just noticeable distortion (JND) gives us a way to model the HVS accurately. In this paper, another very important aspect affecting human perception, visual saliency, is introduced to modulate JND model. Based on the visual saliency’s modulatory effect on JND model which incorporates visual attention’s influence on visual sensitivity, the saliency modulated JND profile guided image watermarking scheme is proposed. The saliency modulated JND profile guided watermarking scheme, where the visual sensitivity model combined with visual saliency’s modulatory effect is fully used to determine image-dependent upper bounds on watermark insertion, allows us to provide the maximum strength transparent watermark. Experimental results confirm the improved performance of our saliency modulated JND profile guided watermarking scheme in terms of transparency and robustness. Our watermarking scheme is capable of shaping lower injected-watermark energy onto more sensitive regions and higher energy onto the less perceptually significant regions in the image, which yields better visual quality of the watermarked image. At the same time, the proposed saliency modulated JND profile guided image watermarking scheme is more robust compared to unmodulated JND profile guided image watermarking scheme.     

Fast image inpainting and colorization by Chambolle’s dual method

In this paper, we propose to use Chambolle’s dual methods to solve Total Variation (TV) inpainting model and (weighted) TV colorization model. The fidelity coefficients in these two models are functions which taking zero in the inpainting region and a positive constant in the other region. Then Chambolle’s dual method can not be directly used to solve these models since the fidelity coefficient will be denominator in the algorithm. In order to overcome this drawback, we propose to approximate these models by adding new variables. Then the approximated problems can be solved by alternating minimization method with Chambolle’s dual method and closed form solutions which is fast and easy to implement. Mathematical results of existence of minimizers are proved for both the original and the approximated problems. Numerical results and comparison with other closely related methods demonstrate that our algorithms are quite efficient.