Chen G.,Advanced Signal Processing Group |
Tian Z.,Advanced Signal Processing Group |
Gong Y.,Advanced Signal Processing Group |
Chen Z.,University of Electronic Science and Technology of China |
Chambers J.A.,Advanced Signal Processing Group
IEEE Transactions on Information Forensics and Security | Year: 2014
This paper considers the security of transmission in buffer-aided decode-and-forward cooperative wireless networks. An eavesdropper which can intercept the data transmission from both the source and relay nodes is considered to threaten the security of transmission. Finite size data buffers are assumed to be available at every relay in order to avoid having to select concurrently the best source-to-relay and relay-to-destination links. A new max-ratio relay selection policy is proposed to optimize the secrecy transmission by considering all the possible source-to-relay and relay-to-destination links and selecting the relay having the link which maximizes the signal to eavesdropper channel gain ratio. Two cases are considered in terms of knowledge of the eavesdropper channel strengths: exact and average gains, respectively. Closed-form expressions for the secrecy outage probability for both cases are obtained, which are verified by simulations. The proposed max-ratio relay selection scheme is shown to outperform one based on a max-min-ratio relay scheme. © 2014 IEEE.
Chanda K.,Advanced Signal Processing Group |
Ahmed W.,Advanced Signal Processing Group |
Mitra S.,Advanced Signal Processing Group
Proceedings of 2015 3rd International Conference on Image Information Processing, ICIIP 2015 | Year: 2015
Vision based hand gesture recognition is an open research problem in Human Computer Interaction (HCI). The most common form of gestures are signs used in different sign languages having both local and global motions. Recognition of these gestures require the hand trajectory both with respect to orientation in space among inter frames and distance among objects like face and hands among intra frames. In this paper, at first the face region and the two hand regions are detected. The centre of the face along with the centre of the two hands are then determined. This is then followed by tracking the hands trajectory following the centre both in terms of direction among consecutive frames as well as distance from the centre of the frame. The variations in the hand locations along with the centre of the face are considered for analysis. Finally the gestures are considered for recognition. The paper addresses a pertinent problem w.r.t the difference in the number of frames between a stored gesture and query gesture for matching. Experimental results show an accuracy of 86% in recognizing 24 gestures is maintained even after normalizing the number of frames by the proposed scheme. © 2015 IEEE.
Chakraborty S.,Advanced Signal Processing Group
2013 4th International Conference on Computing, Communications and Networking Technologies, ICCCNT 2013 | Year: 2013
Now a days it's going to be very much difficult to have trust on digital images. With the advancement and ready availability of image editing software, a digital image can be manipulated so elegantly that there should be no visual clues of manipulation. So it is very much necessary to detect whether a digital image is an original one or some modifications is done after snapped by camera. In this paper a new technique is proposed to detect copy-move image forgery(or region duplication forgery) based on Mutual Information of different regions of an image. No parameter tuning is required for this technique. Experimental results show that this technique is valid for detection of copy moved regions in an digital image and also quite robust to illumination variation. © 2013 IEEE.