Image distortion analysis based on normalized perceptual information distance

Image distortion analysis is a fundamental issue in many image processing problems, including compression, restoration, recognition, classification, and retrieval. Traditional image distortion evaluation approaches tend to be heuristic and are often limited to specific application environment. In this work, we investigate the problem of image distortion measurement based on the theory of Kolmogorov complexity, which has rarely been studied in the context of image processing. This work is motivated by the normalized information distance (NID) measure that has been shown to be a valid and universal distance metric applicable to similarity measurement of any two objects (Li et al. in IEEE Trans Inf Theory 50:3250–3264, 2004). Similar to Kolmogorov complexity, NID is non-computable. A useful practical solution is to approximate it using normalized compression distance (NCD) (Li et al. in IEEE Trans Inf Theory 50:3250–3264, 2004), which has led to impressive results in many applications such as construction of phylogeny trees using DNA sequences (Li et al. in IEEE Trans Inf Theory 50:3250–3264, 2004). In our earlier work, we showed that direct use of NCD on image processing problems is difficult and proposed a normalized conditional compression distance (NCCD) measure (Nikvand and Wang, 2010), which has significantly wider applicability than existing image similarity/distortion measures. To assess the distortions between two images, we first transform them into the wavelet transform domain. Assuming stationarity and good decorrelation of wavelet coefficients beyond local regions and across wavelet subbands, the Kolmogorov complexity may be approximated using Shannon entropy (Cover et al. in Elements of information theory. Wiley-Interscience, New York, 1991). Inspired by Sheikh and Bovik (IEEE Trans Image Process 15(2):430–444, 2006), we adopt a Gaussian scale mixture model for clusters of neighboring wavelet coefficients and a Gaussian channel model for the noise distortions in the human visual system. Combining these assumptions with the NID framework, we derive a novel normalized perceptual information distance measure, where maximal likelihood estimation and least square regression are employed for parameter fitting. We validate the proposed distortion measure using three large-scale, publicly available, and subject-rated image databases, which include a wide range of practical image distortion types and levels. Our results demonstrate the good prediction power of the proposed method for perceptual image distortions.     

An Improved Full Rate Full Diversity QOSTBC with Linear Decoding in MIMO Systems

In this letter, we propose an improved Quasi-orthogonal space-time block code (QOSTBC) with full rate, full diversity, linear decoding and better peak-to-average power ratio (PAPR). Constellation rotation is used to the input symbol vector to ensure full diversity, and then the information symbol vector is interleaved in coordinates and pre-grouped by using a Given rotation matrix. The performance is evaluated by numerical experiments. The PAPR of our proposed QOSTBC is lower than that of CI-QOSTBC in Khan and Rajan (IEEE Trans Inf Theory 52(5):2062–2091, 2006). Meanwhile, the Bit-error-rate versus Signal-to-noise-ratio of our proposed QOSTBC is better than those of OSTBC (Tarokh et al. in IEEE Trans Inf Theory 45(5):1456–1467, 1999) QOSTBC (Jafarkhani in IEEE Trans Wirel Commun 49(1):1–4, 2001), G-QOSTBC (Park et al. in IEEE Commun Lett 12(12):868–870, 2008), slightly better that of the CI-QOSTBC, and as same as that of the recently proposed Minimum Decoding Complexity QOSTBCs (MDC-QOSTBC) in Yuen et al.(IEEE Trans Wirel Commun 4(5):2089–2098, 2005), Wang and Xia (IEEE Trans Inf Theory 55(3):1104–1130, 2009). Compared with MDC-QOSTBC, the proposed QOSTBC has simpler code construct and lower decoding complexity.     

A Fuzzy Switching Median Filter of Impulses in Digital Imagery (FSMF)

This paper proposed a fuzzy-based switching technique that aims at detection and filtering of impulse noises from digital images. Two types of noise models are used to obtain the noisy images. In this two-step process, the noise-free pixels are remained unchanged. The proposed detection algorithm uses 5 \(\times \) 5 window, based on all neighboring pixels on the center of the window of a noisy pixel. Two weighted median filters are devised, and a particular one is applied selectively to the noisy pixel based on the characteristics of the neighboring pixels within the window. Instead of a single threshold, two threshold values are used in the proposed fuzzy membership function to partition the noise level, and accordingly, a filtering method is applied to restore the corrupted pixel. Experimental results show that the proposed technique outperforms the existing impulse denoising methods in terms of peak signal-to-noise ratio and visual effects, with a comparable time complexity with the existing methods.     

Adaptive Power Allocation for Maximizing the Sum Rate of Multiple Interfering Links Under Minimum Rate Constraints

An adaptive power control algorithm is proposed to maximize the sum rate of multiple interfering links under minimum rate constraints. The proposed algorithm efficiently minimizes the outage probability of total network system by using an iterative algorithm with complexity of \(O\left( {N^{2}\ln N} \right) \) , where \(N\) is the number of interfering links. By Monte Carlo simulations, it is shown that the proposed algorithm guarantees the optimum outage probability and the system sum rate above 80 %, compared with the geometric programming (Chiang et al in IEEE Trans Wirel Commun 6(7):2640–2651, 2007).     

High-resolution estimation of the directions-of-arrival distribution by algebraic phase unwrapping algorithms

We present nontrivial utilization methods of a pair of symbolic algebraic algorithms (Yamada et?al. in IEEE Trans Signal Process 46:1639?C1664, 1998; Yamada and Bose in IEEE Trans Circuits Syst 1 Fundam Theory Appl 49:298?C304, 2002) which were developed originally for multidimensional phase unwrapping and zero-distribution problems. Given the minor subspace of the covariance matrix of the data measured at a uniform linear array of sensors, the proposed methods provide estimates of the Directions-of-Arrival (DOA) distribution of multiple narrowband signals, i.e., the number of DOA in an arbitrarily specified range, without using any numerical search for each direction of arrival. The proposed methods can serve as powerful mathematical tools to extract global information in the high-resolution DOA estimation problems.     

A Novel Redundant Binary Number to Natural Binary Number Converter

Redundant binary number appears to be appropriate for high-speed arithmetic operation, but the delay and hardware cost associated with the conversion from redundant binary (RB) to natural binary (NB) number is still a challenging task. In the present investigation a simple approach has been adopted to achieve high speed with lesser hardware and power saving. A circuit level approach has been adopted to implement the equivalent bit conversion algorithm (EBCA) (Kim et al. IEEE Journal of Solid State Circuits 36:1538-1544, 2001, 38:159-160, 2003) for RB to NB conversion. The circuit is designed based on exploration of predictable carry out feature of EBCA algorithm. This implementation concludes a significant delay power product and component complexity advantage for a 64-bit RB to NB conversion using novel carry-look-ahead equivalent bit converter.     

Securely Obfuscating Re-Encryption

We present a positive obfuscation result for a traditional cryptographic functionality. This positive result stands in contrast to well-known impossibility results (Barak et al. in Advances in Cryptology??CRYPTO??01, 2002), for general obfuscation and recent impossibility and implausibility (Goldwasser and Kalai in 46th IEEE Symposium on Foundations of Computer Science (FOCS), pp.?553?C562, 2005) results for obfuscation of many cryptographic functionalities. Whereas other positive obfuscation results in the standard model apply to very simple point functions (Canetti in Advances in Cryptology??CRYPTO??97, 1997; Wee in 37th ACM Symposium on Theory of Computing (STOC), pp.?523?C532, 2005), our obfuscation result applies to the significantly more complex and widely-used re-encryption functionality. This functionality takes a ciphertext for message m encrypted under Alice??s public key and transforms it into a ciphertext for the same message m under Bob??s public key. To overcome impossibility results and to make our results meaningful for cryptographic functionalities, our scheme satisfies a definition of obfuscation which incorporates more security-aware provisions.     

Node coloring based replica detection technique in wireless sensor networks

Node replication attack possess a higher level of threat in wireless sensor networks. A replicated node takes advantage of having legal identity of the compromised node to control the network traffic and inject malicious information into the network. Several techniques have been proposed to detect node replication in wireless sensor networks. However, in most of these techniques, the responsibility for replica detection lies either with the base station or a few randomly selected witness nodes. In this paper, we propose a technique for detecting replicas without the participation of base station and witness nodes. In the proposed scheme, each node is assigned with a color (value), which is unique within its neighborhood. A color conflict within the neighborhood of a node is detected as a replica. We made a comparison of the proposed scheme with RED (Conti et al. in IEEE Trans Dependable Secure Comput 8(5):685–698, 2011), LSM (Parno et al. in Proceedings of IEEE symposium on security and privacy. IEEE, pp 49–63, 2005), and SET (Choi et al. in Proceedings of third international conference on security and privacy in communications networks and the workshops, SecureComm 2007. IEEE, pp 341–350, 2007). Parameters considered for comparison are detection probability, communication complexity and storage overhead. We observed that the proposed scheme has a higher detection probability, and lower communication and storage overhead.     

Palm-Dorsal Vein Recognition Method Based on Histogram of Local Gabor Phase XOR Pattern with Second Identification

This paper proposes a palm-dorsal vein recognition method with local Gabor phase features, which includes a second identification for more accuracy. First, we extract quadrant-bit codes from the 2D Gabor transformation of a vein image. Then using the Histogram of the Local Gabor Phase XOR Pattern (HLGPXP) obtains the vein texture features, which combines the global information and the local information. Finally, the chi-square distance is adopted for recognition. Using the texture features based on the local Gabor codes above, the Second Identification (SI) segments the vein images and regards the non-overlap degree between images as a matching criterion. The experimental results show the Error Equation Rate (EER) of our method (HLGPXP-SI) decreases by 11.7 %, 4.8 % respectively than Modified Local Binary Pattern (MLBP) [1], Local Gabor Binary Pattern (LGBP) [2] on Database A (204 high-quality palm-dorsal vein images from 68 hands), and on Database B (400 low-quality palm-dorsal vein images from 100 hands), it decreases by 18.94 %, 15.51 % respectively than Selected Gabor Phase and Amplitude Features (SGPAF) [3], Direct Gabor Phase Coding (DGPC) [4].     

Performances of chaos-coded modulation concatenated with Alamouti’s space–time block code

Recently, some works have shown that it was possible to obtain quite good bit error rate performances over an additive white Gaussian noise channels with chaotic systems. In this research field, this paper proposes new insights for the chaos-coded modulation (CCM) schemes originally proposed by Kozic et al. (2003; IEEE Trans Circuits Syst Regul Pap 53:2048–2059, 2006). A detailed study of the distance spectrum of such schemes is proposed and an approximation of its distribution by means of Gaussian or Rayleigh mixtures is given. Furthermore, using these approximate distributions, a complete study of the performances of these CCM schemes when they are concatenated with a space–time block code is proposed. Accurate bounds are obtained even in the case of time-selective channels.     

Reanalyzing the basic bandgap reference voltage circuit considering thermal dependence of bandgap energy

The basic bandgap reference voltage generator, BGR, is thoroughly analyzed and relations are reconstructed considering dependency of bandgap energy, E_g, to absolute temperature. The previous works all consider E_g as a constant, independent of temperature variations. However, E_g varies around 25 meV when the temperature is increased from 2 to 92 °C. In this paper the dependence of E_g to absolute temperature, based on HSPICE mosfet models in HSPICE MOSFET Models Manual (Version X-2005.09, 2005), is approximated by a third-order polynomial using Lagrangian interpolating method within the temperature range of 2–92 °C. Accurate analysis on the simplified polynomial reveals that the TC of V_BE must be corrected to ?1.72 mV/°K at 27 °C which has been formerly reported about ?1.5 mV/°K in Razavi (Design of analog CMOS integrated circuits, 2001) and Colombo et al. (Impact of noise on trim circuits for bandgap voltage references, 2007), ?2 mV/°K in Gray et al. (Analysis and design of analog integrated circuits, 2001), Leung and Mok (A sub-1-V 15-ppm/°C CMOS bandgap voltage reference without requiring low threshold voltage device, 2002), Banba et al. (A CMOS bandgap reference circuit with sub-1-V operation, 1999), and ?2.2 mV/°K in Jones and Martin (Analog integrated circuit design, 1997), Tham and Nagaraj (A low supply voltage high PSRR voltage reference in CMOS process, 1995). Another important conclusion is that the typical weighting coefficient of TC+ and TC? terms is modified to about 19.84 at 27 °C temperature from otherwise 16.76, when E_g is considered constant, and also 17.2, in widely read literatures, (Razavi in Design of analog CMOS integrated circuits, 2001). Neglecting the temperature dependence of E_g might introduce a relative error of about 20.5 % in TC of V_BE. Also, resistance and transistor size ratios, which denote the weighting coefficient of TC+ term, might be encountered to utmost 20.3 % error when the temperature dependence of E_g is ignored.     

The Performance of the Adaptive Aggregation Mechanism (AAM) Under Mixed Traffic Loads

The adaptive packet aggregation algorithm (AAM) has been shown to have a superior performance over the first-in first-out (FIFO) algorithm in terms of the throughput and delay (Deng and Davis in International conference on wireless communications and signal processing 2013 (WCSP2013), Hangzhou, China, pp 449–504, 2013; 20th IEEE symposium on communications and vehicular technology in the Benelux 2013 (IEEE SCVT 2013), Namur, 2013). In this paper, we will show that when compared with the FIFO and smallest-size first-served algorithms, the AAM algorithm has the best performances in terms of the trade-off between the overhead saving and the average delay under mixed traffic loads in wireless LANs. The simulation results show that the AAM algorithm produces the largest average aggregate packet size.     

A hybrid multiagent routing approach for wireless ad hoc networks

Wireless ad-hoc networks are infrastructureless networks that comprise wireless mobile nodes able to communicate each other outside wireless transmission range. Due to frequent network topology changes in one hand and the limited underlying bandwidth in the other hand, routing becomes a challenging task. In this paper we present a novel routing algorithm devoted for mobile ad hoc networks. It entails both reactive and proactive components. More precisely, the algorithm is based on ant general behavior, but differs from the classic ant methods inspired from Ant-Colony-Optimization algorithm [1]. We do not use, during the reactive phase, a broadcasting technique that exponentially increases the routing overhead, but we introduce a new reactive route discovery technique that considerably reduces the communication overhead. In the simulation results, we show that our protocol can outperform both Ad hoc On-demand Distance Vector (AODV) protocol [2], one of the most important current state-of-the-art algorithms, and AntHocNet protocol [5], one of the most important ant-based routing algorithms, in terms of end-to-end delay, packet delivery ratio and the communication overhead.     

Directional switching median filter using boundary discriminative noise detection by elimination

We propose an accurate and efficient noise detection algorithm for impulse noise removal, called the boundary discriminative noise detection by elimination (BDNDE), which retains the good characteristics of the BDND filter proposed by Ng and Ma (in IEEE Trans. Image Process. 15(6):1506?C1516, 2006) while suppressing noise effectively. In order to determine whether a pixel is corrupted, the algorithm first sets the minimum and maximum boundary (threshold) values based on the localized window centered on the pixel. The thresholding helps in achieving low false-alarm and miss-detection rate (even in random noise), even up to 90% noise densities. Extensive simulation results, conducted on gray scale images under a wide range (from 10 to 90%) of noise corruption, clearly demonstrate that our enhanced switching median filter gives better results compared to existing BDND median-based filters, in terms of suppressing impulse noise while preserving image details. The proposed method is algorithmically simple and faster, compared to existing BDND, and more suitable for real-time implementation and application. The new method has shown superior performance in terms of subjective quality in the filtered image as well as objective quality in the peak signal-to-noise ratio (PSNR) measurement to that of the BDND filter.     

Reduced Order Observer for Linear Time-Invariant Multivariable Systems with Unknown Inputs

This paper presents the design of a new reduced order observer to estimate the state for a class of linear time-invariant multivariable systems with unknown inputs. The proposed design approach is a combination of the approaches proposed by Hou and Muller (IEEE Trans. Autom. Control 37:871–875, 1992) and Boubaker (Int. J. Autom. Control Syst. Eng. 5:45–51, 2005); matrix decompositions, state transformations, and substitutions based on coordinate changes are used. It is shown that the problem of reduced order observers for linear systems with unknown inputs can be reduced to a standard one (the unknown input vector will not interfere in the observer equations). The effectiveness of the suggested design algorithm is illustrated by a numerical example (aircraft lateral motion), and, for the same aircraft dynamics, we compare our new observer with other already existing observers from the existence conditions and dynamic characteristics point of view; the superiority of the new designed observer is demonstrated.     

Enhancements of Trapdoor Permutations

We take a closer look at several enhancements of the notion of trapdoor permutations. Specifically, we consider the notions of enhanced trapdoor permutation (Goldreich, Foundation of Cryptography: Basic Applications, 2004) and doubly enhanced trapdoor permutation (Goldreich, Computational Complexity: A Conceptual Perspective, 2011) as well as intermediate notions (Rothblum, A Taxonomy of Enhanced Trapdoor Permutations, 2010). These enhancements arose in the study of Oblivious Transfer and NIZK, but they address natural concerns that may arise also in other applications of trapdoor permutations. We clarify why these enhancements are needed in such applications, and show that they actually suffice for these needs.     

A Note on Constant-Round Zero-Knowledge Proofs of Knowledge

In this note, we show the existence of constant-round computational zero-knowledge proofs of knowledge for all $\mathcal {NP}$ . The existence of constant-round zero-knowledge proofs was proven by Goldreich and Kahan (Journal of Cryptology, 1996), and the existence of constant-round zero-knowledge arguments of knowledge was proven by Feige and Shamir (CRYPTO, 1989). However, the existence of constant-round zero-knowledge proofs of knowledge for all $\mathcal {NP}$ is folklore, to the best of our knowledge, since no proof of this fact has been published.     

Concurrent Zero Knowledge, Revisited

We provide a more general and, in our eyes, simpler variant of Prabhakaran, Rosen and Sahai’s (FOCS ’02, pp. 366–375, 2002) analysis of the concurrent zero-knowledge simulation technique of Kilian and Petrank (STOC ’01, pp. 560–569, 2001).     

Algebraic integer architecture with minimum adder count for the 2-D Daubechies 4-tap filters banks

A multiplierless architecture based on algebraic integer representation for computing the Daubechies 4-tap wavelet transform for 1-D/2-D signal processing is proposed. This architecture improves on previous designs in a sense that it minimizes the number of parallel 2-input adder circuits. The algorithm was achieved using numerical optimization based o exhaustive search over the algebraic integer representation. The proposed architecture furnishes exact computation up to the final reconstruction step, which is the operation that maps the exactly computed filtered results from algebraic integer representation to fixed-point. Compared to Madishetty et al. (IEEE Trans Circuits Syst I (Accepted, In Press), 2012a), this architecture shows a reduction of \(10\cdot n-3\) adder circuits, where \(n\) is the number of wavelet decomposition levels. Standard \(512\times 512\) images Mandrill, Lena, and Cameraman were submitted to digital realizations of both proposed algebraic integer based as well as fixed-point schemes, leading to quantifiable comparisons. The design is physically implemented for a 4-level 2-D decomposition using a Xilinx Virtex-6 vcx240t-1ff1156 FPGA device operating at up to a maximum clock frequency of 263.15 MHz. The FPGA implementation is tested using hardware co-simulation using an ML605 board with clock of 100 MHz. A 45 nm CMOS synthesis shows improved clock frequency of better than 500 MHz for a supply voltage of 1.1 V.