Abstract: Algorithmic parameterization and hardware architectures can ensure secure transmission of multimedia data in resource-constrained environments such as wireless video surveillance networks, tele-medicine frameworks for distant health care support in rural areas, and Internet video streaming. Joint multimedia compression and encryption techniques can significantly reduce the computational requirements of video processing systems. We present an approach to reduce the computational cost of multimedia encryption, while also preserving the properties of compressed video (useful for scalability, transcoding, and retrieval), which endanger loss by naive encryption. Hardware-amenable design of proposed algorithms makes them suitable for realtime embeddedmultimedia systems. This approach alleviates the need of additional hardware for encryption in resourceconstrained scenario, and can be otherwise used to augment existing encryption methods used for content delivery in Internet or other applications. In this work, we show how two compression blocks for video coding: a modified frequency transform (called as Secure Wavelet Transform or SWT) and a modified entropy coding scheme, (called Chaotic Arithmetic Coding (CAC)) can be used for video encryption. Experimental results are shown for selective encryption using proposed schemes.
Abstract: Nagaraj et al.[1, 2] present a skewed-non-linear Generalized Luroth Series (s-nGLS) framework.
S-nGLS uses non-linear maps for GLS to introduce a security parameter a which is used to build
a keyspace for image or data encryption. The map introduces non-linearity to the system to add
an “encryption key parameterâ€. The skew is added to achieve optimal compression efficiency.
s-nGLS used as such for joint encryption and compression is a weak candidate, as explained in
this communication. First, we show how the framework is vulnerable to known plaintext based
attacks and that a key of size 256 bits can be broken within 1000 trials. Next, we demonstrate that
the proposed non-linearity exponentially increases the hardware complexity of design. We also
discover that s-nGlS can’t be implemented as such for large bitstreams. Finally, we demonstrate
how correlation of key parameter with compression performance leads to further key vulnerabilities.
Abstract: Many modern computing applications have been enabled through the use of real-time multimedia
processing. While several hardware architectures have been proposed in the research literature
to support such primitives, these fail to address applications whose performance and resource
requirements have a dynamic aspect. Embedded multimedia systems typically need a power
and computation efficient design in addition to good compression performance. In this paper, we
introduce a PolymorphicWavelet Architecture (Poly-DWT) as a crucial building block towards the
development of embedded systems to address such challenges. We illustrate how our Poly-DWT
architecture can potentially make dynamic resource allocation decisions, such as the internal bit
representation and the processing kernel, according to the application requirements. We introduce
a filter switching architecture that allows for dynamic switching between 5/3 and 9/7 wavelet
filters and leads to a more power efficient design. Further, a multiplier-free design with a low
adder requirement demonstrates the potential of Poly-DWT for embedded systems. Through an
FPGA prototype, we perform a quantitative analysis of our Poly-DWT architecture, and compare
our filter to existing approaches to illustrate the area and performance benefits inherent in our
approach.
Abstract: There has been an increasing concern for the security of multimedia transactions over real-time embedded systems. Partial and selective encryption schemes have been
proposed in the research literature, but these schemes significantly increase the computation cost leading to tradeoffs in system latency, throughput, hardware requirements and
power usage. In this paper, we propose a light-weight multimedia encryption strategy based on a modified Discrete Wavelet Transform (DWT) which we refer to as the Secure
Wavelet Transform (SWT). The SWT provides joint multimedia encryption and compression by two modifications over the traditional DWT implementations: (a) parameterized
construction of the DWT and (b) subband re-orientation for the wavelet decomposition. The SWT has rational coefficients which allow us to build a high throughput hardware
implementation on fixed point arithmetic. We obtain a zero-overhead implementation on custom hardware. Furthermore, a Look-up table based reconfigurable implementation
allows us to allocate the encryption key to the hardware at run-time. Direct implementation on Xilinx Virtex FPGA gave a clock frequency of 60 MHz while a reconfigurable
multiplier based design gave a improved clock frequency of 114 MHz. The pipelined implementation of the SWT achieved a clock frequency of 240 MHz on a Xilinx Virtex-4 FPGA and met the timing constraint of 500 MHz on a standard cell realization using 45nm CMOS technology
Abstract: The availability of cheap network based video cameras and the prevalence of wireless networks has lead to a major thrust towards deployment of large scale Distributed Video Surveillance (DVS) systems. This has opened up an important area of research to deal with the issues involved in DVS system for efficient collection and transmission of large scale video streams from the cameras at the guarded sites, to the end users in possibly constrained network conditions. In this paper, we propose a framework based on content-based video classification and scalable compression scheme to provide a robust bandwidth efficient video transmission for DVS. The scheme builds on a Discrete Wavelet Transform (DWT) based Color-Set Partitioning for Hierarchical Trees (CSPIHT) coding to obtain a scalable bitstream. Wavelet domain segmentation and compression assists in development of a DVS architecture. The architecture includes a novel module for dynamic allocation of Network bandwidth based on the current available resources and constraints. Different frame constituents are optimally coded based on their relative significance, perceptual quality, and available estimate of network bandwidth. Experimental result over different video sequences and simulations for Network conditions demonstrate the efficient performance of the approach.
Abstract: Multi-core processors can deliver significant performance benefits for multi-threaded software by adding processing power with minimal latency, given the proximity of the processors. Cryptographic applications are inherently complex and involve large computations. Most cryptographic operations can be translated into logical operations, shift operations, and table look-ups. In this paper we design a novel processor (called mu-core) with a reconfigurable Arithmetic Logic Unit, and design custom two-dimensional multi-core architectures on top of it to accelerate cryptographic kernels. We propose an efficient mapping of instructions from the multi-core grid to the individual processor cores and illustrate the performance of AES-128E algorithm over custom-sized grids. The model was developed using Simulink and the performance analysis suggests a positive trend towards development of large multi-core (or multi- µ-core) architectures to achieve high throughputs in cryptographic operations.
Abstract: Chaotic filter bank schemes have been proposed in research literature
to allow efficient encryption of data for real-time embedded systems. Some security
flaws are found in the underlying approach which makes such a scheme unsafe
for real-life applications. In this paper, we first present an improved scheme to
alleviate the weaknesses of chaotic filter bank scheme, and add enhanced security
features, to form a Modified Chaotic Filter Bank (MCFB) scheme. A reconfigurable
hardware implementation of the MCFB scheme is presented next. Implementation on
reconfigurable hardware speeds up the performance of such a scheme as the filter bank
as well as chaotic generator by mapping the multipliers in the design to reconfigurable
Look-Up Tables. An optimized implementation on Xilinx Virtex-5 VLX330 FPGA gave
a speedup of 30% over non-optimized direct implementation. A clock frequency of 88
MHz was obtained.
Abstract: This paper presents a practical solution to make remote laboratories a realizable dream. A remote laboratory is an online laboratory where students can get first-hand experience of engineering labs via internet. Video transmission can provide hands on experience to the user but the transmission channel or networks typically have variable and low bandwidth that poses a tough constraint for such implementation. This work presents a practical solution to such problems by adaptively transmitting the best available quality of laboratory videos to the user depending on network bandwidth. The concept behind our work is that not all objects or frames of the video have equal importance, and thus bandwidth reduction can be accomplished by intelligently transmitting important parts at relatively higher resolution. A localized Time adaptive mean of Gaussian (L-TAMOG) approach is used to search for moving objects which are then allocated network resources dynamically according to the varying network bandwidth variations. Adaptive motion compensated wavelet based encoding is used to achieve scalability and high compression. The proposed system tracks the network bandwidth and delivers optimally the most important contents of video to the student. Experimental results over several remote laboratory sequences show the efficiency of the proposed framework.
Abstract: A serious bottleneck in multimedia E-learning is the non-availability of required bandwidth. While much research has been done on multimedia compression and network resource optimization, multimedia delivery is still a big concern especially for scarce resource networks. The virtues of network aware video coding and application of domain specific compression techniques have not yet been fully explored. In this paper we deal with the issue of intelligent transmission of important segments of the video sequence over the network. We incorporate the knowledge of the network conditions to determine how various parts of the video frames are encoded. An estimate of the available network bandwidth is obtained which is then distributed optimally between the different frame constituents based on their relative importance and motion. We have incorporated the concept of phase shifted frame packaging that provides video transmission with better perceptual quality, reduced retransmissions and reduced jitters in case of packet losses. While this scheme is operational for all low motion videos with identifiable visual objects, we take the example of educational videos to demonstrate the proposed scheme.
Abstract: Multimedia QoS is a big concern, especially for the scarce resource networks.
This paper deals with the issue of intelligent transmission of important segments of the video
sequence over the network. An estimate of the available network bandwidth is obtained, which is
then distributed optimally between the different frame constituents based on their relative
importance and motion by the bandwidth allocation module. Color Embedded Zerotree Wavelet
(CEZW) coding is used to obtain a scalable bitstream that provides dynamic response to
changing network conditions. This scheme is robust and operational for all low motion videos
with identifiable VOs.
Abstract: Image denoising is an important step in image compression and other image processing algorithms. Hard and soft thresholding algorithms are often used to denoise the images. Recently wavelet transform has been used as a tool to denoise the images. However, there are problems associated with the thresholding algorithms. There is no subjective way to determine the threshold. In this work, we develop a simple Bayesian theory to obtain optimal threshold for such algorithms. MATLAB simulations were performed to validate the working of Bayesian thresholding method.
Abstract: In this paper we propose a three-dimensional vector quantization based video coding scheme. The algorithm uses a 3D vector quantization pyramidal code book based model with adaptive code book pyramidal codebook for compression. The pyramidal code book based model helps in getting high compression in case of modest motion. The adaptive vector quantization algorithm is used to train the code book for optimal performance with time. Some of the distinguished features of our algorithm are its excellent performance due to its adaptive behavior to the video composition and excellent compression due to codebook approach. We also propose an efficient codebook based post processing technique which enables the vector quantizer to possess higher correlation preservation property. Based on the special pattern of the codebook imposed by post-processing technique, a window based fast search (WBFS) algorithm is proposed. The WBFS algorithm not only accelerates the vector quantization processing, but also results in better rate-distortion performance.
The proposed approach can be used for both teleconferencing videos and to compress images obtained from confocal laser scanning microscopy (CLSM). The results show that the proposed method gave higher subjective and objective image quality of reconstructed images at a better compression ratio and presented more acceptable results when applying image processing filters such as edge detection on reconstructed images. The experimental results demonstrate that the proposed method outperforms the teleconferencing compression standards H.261 and LBG based vector quantization technique.
Abstract: Carrier Aggregation (CA) in LTE-Advanced yields
higher data rates to the User Equipments (UE). The existing
schemes for CA lack channel-awareness leading to unfair allocation
and aggregation of carriers to UEs.The cell-edge users
particularly suffer from exhaustion of resources, higher fading
losses, lower SINR values (and hence higher power consumption
in uplink) and channel-blind assignment often implies that their
traffic requirements are least satisfied. This paper addresses
the above concern by proposing an edge-prioritized channeland
traffic-aware uplink CA comprising of Component Carrier
(CC) assignment and resource scheduling. The LTE-A UEs are
spatially grouped and the under-represented groups (such as
the ones comprising edge UEs) are prioritized for CA. This
results in assigning the best channels to the edge groups. The
Physical Resource Blocks (PRBs) are assigned to the groups
based on Proportional Fair Packet Scheduling (PFPS) in the
time domain while frequency domain PFPS is used to address
resource contention amongst individual UEs in a group. The
proposed approach outperforms the existing channel-blind and
opportunistic RRM techniques by 33% in CC assignment and
21% in PFPS.
Abstract: In this work, we discuss an interpretation of arithmetic coding using chaotic maps. We present a hardware implementation using 64 bit fixed point arithmetic on Virtex-6 FPGA (with and without using DSP slices). The encoder resources are slightly higher than a traditional AC encoder, but there are savings in decoder performance. The architectures achieve clock frequency of 400-500 MHz on Virtex-6 xc6vlx75 device.
Abstract: Long Term Evolution (LTE) is emerging as a major candidate for 4G cellular networks to satisfy the increasing demands for mobile broadband services, particularly multimedia delivery. MIMO (Multiple Input Multiple Output) technology combined with OFDMA and more efficient modulation/coding schemes (MCS) are key physical layer technologies in LTE networks. However, in order to fully utilize the benefits of the advances in physical layer technologies MIMO configuration and MCS need to be dynamically adjusted to derive the promised gains of 4G at the application level. This paper provides a performance evaluation of video traffic with variations in the physical layer transmission parameters to suit the varying channel conditions. A quantitative analysis is provided using the perceived video quality (evaluated using no-reference blocking and blurring metrics) along with transmission delay, as video quality measures. Experiments are performed to measure performance with changes in modulation as well as code rates in poor and good channel conditions. We discuss how an adaptive scheme can optimize the performance over a varying channel.
Abstract: he combination of increased data rates in 4G
cellular networks (such as LTE Advanced), dedicated multicast/
broadcast services (e-MBMS) and the emergence of scalable video
coding standards (H.264 SVC) allow mobile operators to offer
multimedia-based services with a high quality of experience to
end users. H.264 SVC offers three dimensions of scalability v.i.z.
Quality (SNR), Temporal and Spatial.
In this paper we investigate the use of Scalable Video Coding
(SVC) for video delivery over an LTE network. In particular, we
carried on a two step performance evaluation: first, we perform
a static analysis on how different types of scalability influences
the video quality, then, we analyze through simulations how the
transmission over a wireless means further affects the quality.
In our analysis, we adopted a wide range of metrics: 2 fullreference
metrics, namely PSNR and SSIM, along with 2 noreference
metrics, MSU Blocking and Blurring.
Our results show that no-reference evaluation metrics could
be employed alongside a frame-drop metric in the place of fullreference
metrics. Moreover, we show that the video scalability
alone is not sufficient to avoid a degradation of quality, in some
cases in the order of seconds, when caused by packet loss.
Abstract: Chaotic encryption schemes are believed to provide greater level of security than conventional ciphers. In this paper, a chaotic stream cipher is first constructed and then its hardware implementation details over FPGA are provided. Logistic map is the simplest chaotic system and has high potential to be used to design a stream cipher for real-time embedded systems. The cipher uses a pseudo-random sequence generator based on modified logistic map (MLM) and a random feedback scheme. MLM has better chaotic properties than the logistic map in terms of uniformity of bifurcation diagram and at also avoids the stable orbits of logistic map giving a more chaotic behavior to the system. The proposed cipher gives 16 bits of encrypted data per clock cycle. The hardware implementation results over Xilinx Virtex-6 FPGA give a synthesis clock frequency of 93 MHz and
a throughput of 1.5 Gbps while using 16 hardware multipliers.This makes the cipher suitable for embedded devices which have tight constraints on power consumption, hardware resources and real-time parameters.
Abstract: This paper introduces a reconfigurable architecture for ensuring secure and real-time video delivery through a novel parameterized construction of the Discrete Wavelet Transform DWT). This parameterized construction promises multimedia encryption and is also well-suited to a hardware implementation due to our derivation of rational filter coefficients. We achieve an efficient and high-throughput reconfigurable hardware implementation through the use of LUT-based constant multipliers enabling run-time reconfiguration of encryption key. We also compare our prototype (using a Xilinx Virtex 4 FPGA) to several existing implementations in the research literature and show that we achieve superior performance as compared to both traditional CPU-based and custom VLSI approaches while adding features for secure multimedia delivery.
Abstract: Joint Video Compression and Encryption (JVCE)
has gained increased attention in the past couple of years to
reduce the computational complexity of video compression, as
well as provide encryption of multimedia content for web services.
In this paper, we present a JVCE framework based on Binary
Arithmetic Coding (BAC). We first present an interpretation of
BAC in terms of a skewed binary map and then describe 7
other possible chaotic maps which give similar Shannon optimal
performance as BAC. We then propose a modification of BAC
in which the overall length within the range [0,1) allocated
to each symbol is preserved, but the choice of map used to
encode each symbol is based on a key. The encoder, referred
to as Chaotic Binary Arithmetic Coder (CBAC), has the effect
of scrambling the intervals without making any changes to the
width of interval in which the codeword must lie, thereby allowing
encryption without sacrificing any coding efficiency. We also
present some some security enhancement features to show how
they can alleviate the limitations of our technique against known
cryptanalysis on BAC-based encryption schemes.
Abstract: In this paper we present the design of a novel embedded processor architecture (which we call a μ-core) that makes use of a reconfigurable ALU. This core serves as the basis of custom 2-dimensional array architectures that can be used to accelerate algorithms such as cryptography and image processing. An efficient translation and mapping of instructions from the multi-core grid to the individual processor cores is proposed and illustrated with an implementation of the AES encryption algorithm on custom-sized grids. A simulation model was developed using Simulink and the performance analysis suggests a positive trend towards the development and utilization of such hardware.
Abstract: Real-time multimedia processing empowers many sensitive multimedia services including video surveillance, telemedicine, e-learning etc. While several hardware architectures
have been proposed in the research literature to support these primitives, they fail to address applications whose performance and resource requirements have a dynamic aspect. We introduce a Polymorphic Wavelet Architecture (Poly-DWT) as a crucial building block that can potentially make dynamic resource allocation decisions including power requirements, internal bit representation, number of processing kernels, according to application requirements. We introduce a folded switching filter architecture. It allows for dynamic switching between 5/3 and 9/7 filters and leads to power-efficient design. Further, a multiplier-free design with few adder requirements demonstrates the potential of Poly-DWT for embedded systems. Through an FPGA prototype, we perform a quantitative analysis of our Poly-DWT architecture. Experimental results and comparisons with systems proposed in existing literature demonstrates the superior performance of our approach in static and dynamic aspects.
Notes: The paper was submitted to the Design Contest of VLSI Design conference and awarded as 3rd best entry, and invited for a presentation to the conference.
Abstract: We introduce a zero-overhead encryption and authentication scheme for real-time embedded multimedia systems. The security promises of this scheme come from the parameterized construction of the Discrete Wavelet Transform (DWT) compression block. The parameterized construction provides rational coefficients that lead to efficient fixed point hardware implementation. We achieve a clock speed of over 240 MHz on a Xilinx Vertex V FPGA. A comparison with existing approaches was done to indicate the high throughput and low hardware overhead involved in adding the security feature to DWT architecture.
Abstract: Due to advances in network technology and the prevalence of wireless networks, it has become possible to realize Remote Video Surveillance (RVS) applications as a low cost system using existing infrastructure. However such applications require enormous bandwidth for video transmission and a serious bottleneck is the non-availability of required bandwidth, especially over wireless networks. In this paper we deal with the issue of
intelligent transmission of important segments of the video sequence over the network. Our algorithm eradicates spatial and temporal redundancies and exploits the virtues of content based adaptation for compression. We have used a real time and robust approach to segment out the visual objects from video frames and
used Discrete Wavelet Transform based Color Embedded Zerotree Wavelet (CEZW) coding to obtain a scalable bitstream that provides dynamic response to changing network conditions. An estimate of the available network bandwidth is obtained which is then distributed optimally between the different frame constituents based on their relative importance and motion by the Dynamic Decision Maker (DDM) module. This results in excellent subjective performance due to its adaptive behavior to the network conditions and excellent compression due to the classification of the objects. To achieve packet loss resilience and high quality video reception,
we have used the concept of phase shifted frame packaging. Experimental result over a RVS dataset demonstrates the efficient network performance of our approach.
Abstract: Traditional microprocessor-based solutions are insufficient to serve the dynamic throughput demands of real-time scalable multimedia processing systems. This paper introduces a Polymorphic Architecture for the Discrete Wavelet Transform (Poly-DWT) as a building block of reconfigurable systems to address these needs. We illustrate how our Poly- DWT architecture can dynamically make resource allocation decisions according to application requirements. We perform a quantitative analysis of our Poly-DWT architecture using an FPGA prototype, and compare our filters to existing approaches to illustrate the area and performance benefits inherent in our approach.â€
Abstract: Real-time image and multimedia processing applications such as video surveillance and telemedicine can have
dynamic requirements of system latency, throughput, and power consumption. In this paper we discuss the design of reconfigurable wavelet filters for image processing applications that can meet such dynamic requirements. We generate several efficient hardware designs based on a derived family of bi-orthogonal 9/7
filters. An efficient folded and multiplier-free implementation of a 9/7 filter is obtained with the help of nine adders, which is a significant improvement over other existing approaches. We also propose an architecture that allows for on-the-fly switching between 9/7 and 5/3 filter structures. A performance comparison of these filters and their hardware requirements with other existing approaches demonstrates the suitability of our choice.
Abstract: A serious bottleneck in real-time multimedia applications is the non-availability of required network bandwidth.
While much research has been done on multimedia compression and network resource optimization, multimedia delivery is still a big concern especially for scarce resource networks. The virtues of network aware
video coding and application of domain specific compression techniques have not yet been fully explored. In
this paper we propose a dynamic Network Bandwidth Allocation Scheme which deals with intelligent transmission of the video sequence over the network. We incorporate the knowledge of the network conditions to
determine how various parts of the video frames are encoded. The module is called is called SDM (Smart
Decision Maker) and it builds over an intelligent classification of Video into Visual Objects (VOs). An estimate
of the available network bandwidth is obtained which is then distributed optimally between the different frame
constituents based on their relative importance and motion.
Abstract: Video transmission is required to provide a first hand experience to a distant student in case of mobile engineering laboratory. This makes the task challenging as the user has limited bandwidth. This paper presents a mobile engineering laboratory framework which provides best available quality of laboratory videos to the user in real time. Restriction on bandwidth resources at times of low bandwidth is accomplished by transmitting important parts only at a relatively higher resolution. A localized Time adaptive mean of Gaussian (L-TAMOG) approach is used to search for Motion Blocks or Visual Blocks (VBs) which are then allocated network resources dynamically according to the varying network bandwidth variations. Adaptive motion compensated wavelet based encoding is utilized to achieve scalability and high compression. Our system keeps a track of the network bandwidth and attempts to deliver the user an optimal trade-off between important video sections and the available bandwidth. In scarce resource cases, only the most important contents of video are refreshed for the user. Experimental results over mobile engineering laboratory sequences show the efficiency of the proposed framework.
Abstract: A serious bottleneck in mobile learning is the non-availability and variations of sufficient bandwidth
required for multimedia applications. Mobile systems have currently been researched for learning
applications. While much research has been done on multimedia compression and network resource
optimization, multimedia delivery remains a big concern. In this paper we deal with the issue of intelligent
transmission of video sequence over the mobile network. We also ensure network adaptive content
delivery to the user making our system attractive for real time applications. We incorporate the
knowledge of the network conditions to determine how various parts of the video frames are encoded.
An estimate of the available network bandwidth is then obtained which is distributed optimally between
the different frame constituents based on their relative importance and motion by the bandwidth
allocation module. This approach helps to reach an efficient trade off between perceptual quality of the
video and the available network bandwidth. While this scheme is robust and operational for all low
motion videos with identifiable visual objects, we take the example of educational videos to demonstrate
the proposed scheme. This approach promises great improvement in mobile learning experience of the
users.
Abstract: In this paper, we address the problem of delivery of multimedia services on bandwidth deficient wireless networks for E-learning. We propose a modified continuous rate-scalable wavelet based video compression technique for E-learning lecture videos. The algorithm eradicates spatial and temporal redundancies and exploits the virtues of content based classification for compression. Some of the distinguished features of our algorithm are its excellent subjective performance due to its adaptive behavior to the network conditions and excellent compression due to the classification of the objects in the E-learning lecture video. Also, the compression mechanism maintains high PSNR for prime objects present in the lecture video which further facilitates zooming operations. In this paper, we introduce a noble concept of even and odd frame distinction (EODist). A significant reduction in number of retransmissions of data packets has been observed after integrating EODist with conventional mechanism, which is also a potential advantage of our algorithm in bandwidth deficient wireless network environment. The algorithm exhibits high asymmetry between compressor and de-compressor. The compressor is designed to achieve optimum content based compression using content based wavelet transform and is computationally more complex whereas the decompressor is intentionally designed procedurally simple to support real time de-compression of the compressed data at the client side. The performance of our algorithm is analyzed and its advantages are justified with the help of experimental results
Abstract: Advances in Multimedia technologies are leading to new dimensions to the way education is imparted in institutes and Universities. Non availability of bandwidth serves as a serious bottleneck to view lecture videos at good resolution especially in rural and sub-urban areas. Content adaptive compression can lead to maximization of the utility of the available bandwidth and thus in a way overcome the problem of scarcity of network resources. Our implementation can drastically change the scenario of village education especially in India. In this paper, we present a video compression and streaming technique that dynamically changes the resource requirements according to the importance of a scene and object in a lecture video sequence. Here we present an algorithm that minimizes the temporal and spatial redundancies in lecture videos and gives an optimum level of compression. Results over several educational videos illustrate the high compression performance of our technique.
