Compressed Frames Research Articles

Evaluation of Data Compression Techniques for Video Transmission over Wireless Sensor Networks

Video transmission over WSN is a challenging task because, video data is inherently huge in size and its transmission requires high bandwidth and processing requires more memory and more power. Presently majority of the research work in this area is focused on improving battery life, optimizing network parameters and increasing energy efficiency. The area of best suitable compression scheme for WSN is rarely being explored. This paper focuses on finding out a suitable compression technique for video transmission over WSN. Wireless sensor network (WSN) is an ad-hoc network of sensor nodes, where each node is able to communicate with every other node in the network in single hop or multi-hop manner. It is a low cost, low power and low bandwidth network with each node having limited battery life and limited memory. In order to overcome these challenges, initially image compression is applied on each frame extracted from given video. To find out most suitable compression technique for WSN, the various existing 2D image transforms like DCT, KLT, Slant, Hartley, Hadamard and DST are compared based upon their energy compaction property. The transform that gives more energy compaction is best suitable for WSN. Thus, after selecting a suitable transform for WSN domain, it is applied to obtain compressed video frames. Zigbee protocol based hardware setup is used for serial transmission of RGB video data frames between the nodes. Different parameters are evaluated for received image frames and transmitted image frames. Experimental evaluation shows that zigbee hardware set up improves the reliability and efficiency of video data transmission. This type of WSN set-up can be used for capturing video in any remote and hard-lying (border, mountains, forest) area, where any other types of networks are not available.

Unequal loss protection scheme using a quality prediction model in a Wi-Fi broadcasting system

Wireless local area network–based broadcasting techniques are a type of mobile Internet Protocol television technology that simultaneously transmits multimedia content to local users. Contrary to the existing wireless local area network–based multimedia transmission systems, which transmit multimedia data to users using unicast packets, a wireless local area network–based broadcasting system is able to transmit multimedia data to many users in a single broadcast packet. Consequently, network resources do not increase with the increase in the number of users. However, IEEE 802.11 does not provide a packet loss recovery algorithm for broadcast packet loss, which is unavoidable. Therefore, the forward error correction technique is required to address the issue of broadcast packet loss. The broadcast packet loss rate of a wireless local area network–based broadcasting system that transmits compressed multimedia data is not proportional to the quality deterioration of the received video signals; therefore, it is difficult to predict the quality of the received video while also considering the effect of broadcast packet loss. In this scenario, allocating equal forward error correction packets to compressed frames is not an effective method for recovering broadcast packet loss. Thus, several studies on unequal loss protection have been conducted. This study proposes an effective, prediction-based unequal loss protection algorithm that can be applied to wireless local area network–based broadcasting systems. The proposed unequal loss protection algorithm adopts a novel approach by adding forward error correction packets to every transmission frame while considering frame loss. This algorithm was used as a new metric to predict video quality deterioration, and an unequal loss protection structure was designed, implemented, and verified. The effectiveness of the quality deterioration model and the validity of the unequal loss protection algorithm were demonstrated through experiments.

Proposed enhanced hybrid framework for efficient 3D-MVC and 3D-HEVC wireless communication

The streaming of Three-Dimensional Video (3DV) over erroneous wireless channels causes Macro-Blocks (MBs) corruptions. Thus, the efficient performance of 3DV communication techniques over wireless channels has become an interesting research topic because of the restricted resources and the existence of severe communication losses. The 3DV consists of various video sequences captured via multiple cameras surrounding an object, and working simultaneously. Therefore, there is a need to achieve high encoding efficiency. Unfortunately, the highly-compressed 3DV content is subject to communication channel corruptions. Thus, in this research, we suggest the utilization of a chaotic randomization technique based on Baker map with convolution coding and equalization for high-quality 3D Multi-view Video Coding (MVC) and High Efficiency Video Coding (HEVC) transmission over an Orthogonal Frequency Division Multiplexing (OFDM) wireless system. Rayleigh fading and Additive White Gaussian Noise (AWGN) are considered in this paper in a real scenario of 3DV transmission. Firstly, the 3DV volume is compressed making use of the intra- and inter-prediction correlations between frames. Then, the compressed 3D-MVC and 3D-HEVC frames are converted into binary data format. After that, the chaotic randomization technique is employed before the modulation stage. It is utilized to minimize the channel corruptions on the streamed encoded 3DV data, and it as well introduces a degree of encryption to the transmitted 3DV frames. To evaluate the efficiency of the suggested hybrid framework; different simulations on several 3D-MVC and 3D-HEVC frames have been executed. The results prove that the delivered 3DV frames with the suggested framework have high Peak Signal-to-Noise Ratios (PSNRs).

Efficient hybrid framework for transmission enhancement of composite 3D H.264 and H.265 compressed video frames

Three-Dimensional Multi-View Video (3D-MVV) transmission over wireless networks suffers from losses. Therefore, the robust performance of 3D-MVV transmission techniques over wireless channels has become a recent hot research issue due to the restricted resources and the presence of severe channel errors. The 3D-MVV is composed of multiple video stream shots by several cameras around a single object, simultaneously. So, it is an urgent task to achieve high compression ratios to meet future bandwidth constraints. Unfortunately, the highly-compressed 3D-MVV data becomes more sensitive and vulnerable to packet losses, especially in the case of heavy channel errors. Thus, in this paper, we propose the application of a chaotic Baker map interleaving technique with equalization for efficient transmission of composite 3D-MVV compressed frames over an Orthogonal Frequency Division Multiplexing (OFDM) wireless channel. Rayleigh fading and Additive White Gaussian Noise (AWGN) are considered in the real scenario of 3D-MVV transmission. Firstly, the 3D-MVV content is compressed exploiting the intra- and inter-prediction correlations between frames. After that, a composite frame of luminance is generated from each four consecutive frames using Discrete Cosine Transform (DCT), which represents a second level of compression. The resultant composite frame is converted to binary data format. Then, chaotic interleaving is applied on the binary information prior to the modulation process. This chaotic interleaving is used to mitigate the OFDM induced Peak-to-Average Power Ratio (PAPR) problem and to reduce the wireless channel effects on the transmitted bit streams. It also adds a degree of encryption to the transmitted 3D-MVV compressed frames. To evaluate the performance of the proposed hybrid technique, several simulation experiments on different 3D-MVV frames have been executed. The experimental results show that the received 3D-MVV frames have high average Peak Signal-to-Noise Ratio (PSNR) gains up to 4.25 dB and a reduction of the average PAPR values by about 12 dB with the proposed hybrid technique compared to the other traditional techniques.

Detecting double compressed MPEG videos with the same quantization matrix and synchronized group of pictures structure

Double compression detection is a crucial stage in digital image and video forensics. However, the detection of double compressed videos is challenging when the video forger uses the same quantization matrix and synchronized group of pictures (GOP) structure during the recompression history to conceal tampering effects. A passive approach is proposed for detecting double compressed MPEG videos with the same quantization matrix and synchronized GOP structure. To devise the proposed algorithm, the effects of recompression on P frames are mathematically studied. Then, based on the obtained guidelines, a feature vector is proposed to detect double compressed frames on the GOP level. Subsequently, sparse representations of the feature vectors are used for dimensionality reduction and enrich the traces of recompression. Finally, a support vector machine classifier is employed to detect and localize double compression in temporal domain. The experimental results show that the proposed algorithm achieves the accuracy of more than 95%. In addition, the comparisons of the results of the proposed method with those of other methods reveal the efficiency of the proposed algorithm.

Phase unwinding for dictionary compression with multiple channel transmission in magnetic resonance fingerprinting

PurposeMagnetic Resonance Fingerprinting reconstructions can become computationally intractable with multiple transmit channels, if the B1+ phases are included in the dictionary. We describe a general method that allows to omit the transmit phases. We show that this enables straightforward implementation of dictionary compression to further reduce the problem dimensionality. MethodsWe merged the raw data of each RF source into a single k-space dataset, extracted the transceiver phases from the corresponding reconstructed images and used them to unwind the phase in each time frame. All phase-unwound time frames were combined in a single set before performing SVD-based compression. We conducted synthetic, phantom and in-vivo experiments to demonstrate the feasibility of SVD-based compression in the case of two-channel transmission. ResultsUnwinding the phases before SVD-based compression yielded artifact-free parameter maps. For fully sampled acquisitions, parameters were accurate with as few as 6 compressed time frames. SVD-based compression performed well in-vivo with highly under-sampled acquisitions using 16 compressed time frames, which reduced reconstruction time from 750 to 25min. ConclusionOur method reduces the dimensions of the dictionary atoms and enables to implement any fingerprint compression strategy in the case of multiple transmit channels.

Chaotic Interleaving for the Transmission of Compressed Video Frames with Self-Embedded Digital Signatures

This paper presents an efficient video compression and transmission scheme based on the Set Partitioning In Hierarchical Trees (SPIHT) algorithm and chaotic Baker map interleaving. The compressed video frames have self-embedded digital signatures, and the transmission is performed over Orthogonal Frequency Division Multiplexing wireless systems with equalization. The video frames compressed with SPIHT algorithm are primarily converted to the luminance and chrominance scheme for self-watermark embedding, and then the binary format is reconstructed again. Prior to the modulation step, the chaotic randomization is performed on the binary data to encrypt the data to be transmitted and reduce the noise impact of the multipath channel. For performance evaluation, both Rayleigh and additive noise channels are considered for various video frames with chaotic interleaving. The simulation results reveal that the received watermarked video frames with chaotic interleaving applied achieve higher Peak Signal-to-Noise Ratios and correlation coefficients compared to other approaches.

No Total Totality: Forced Labor, Stalinism, and De-Stalinization

Alan Barenberg, Gulag Town, Company Town: Forced Labor and Its Legacy in Vorkuta. 331 pp. New Haven: Yale University Press, 2014. ISBN-13 9780300179446. $65.00. Anatolii I. Shirokov, Dal'stroi v sotsial'no-ekonomicheskom razvitii SeveroVostokaSSSR (1930-1950-egg.) (Dal 'stroi in the Socioeconomic Development of the Northeastern USSR [1930-1950s]). 654 pp. Moscow: Rosspen, 2014. ISBN-13 978-5824318944. Aleksei V. Zakharchenko, NKVD iformirovanieaviapromyshlennogo kompleksa v Povolzh 'e, 1940-1943 (The NKVD and the Formation of the Aviation Industrial Complex in the Volga Region, 1940-43). 480 pp. Samara: Institut rossiiskoi istorii Rossiiskoi akademii nauk, Povolzhskii filial, 2013. ISBN 978-5934246588. Recent historical writing about the Soviet Union includes notable, muchneeded, and diligent works dedicated to the consolidation, development, and expansion of the prison camp system, as well as the role that it played in the Soviet Union's transition from a dictatorship to an ordinary authoritarian regime. Researchers have made use of new sources to produce valuable work examining the deep internal conditions leading to the expansion of the I Gulag. (1) The books under review are vivid examples of this historiographical trend. Descriptions of the camps and their economic structures, as well as summaries of statistical evidence about the number of prisoners and industrial output--characteristic of earlier Gulag research--are not completely absent from these new works, but they have taken on a secondary role. To a much greater degree, the authors focus on the practices of administering the camp economy and realizing departmental interests; the evolution of inmate society; and implicit or explicit signs of crisis in the Stalinist system of forced labor. Alan Barenberg dedicates his brilliantly written book to the largest division of the Gulag: the camp complex of Vorkuta, in the northern European part of the USSR. The region, ill-suited for habitation but rich in resources (primarily coal), was the ideal place for a Stalinist camp. Vorkuta became the symbol of the camp system for these and many other reasons. After the camp was eliminated, it became an informative example of how the Gulag's economic and social structures evolved and were maintained. Equally emblematic is Anatolii I. Shirokov's subject of study: the notorious Dal'stroi Trust, which mined gold from the rich deposits on the Kolyma river basin in the northeastern USSR. Over a quarter-century (1932-56), the basin yielded 1,200 tons of gold and huge amounts of other nonferrous metals. Around 850,000 prisoners passed through the camps at Kolyma from 1932 to 1953, of whom 120,000 died (482, 638). Aleksei Zakharchenko focuses his study on a lesser-known and smaller, though no less significant, site of Stalinist forced labor. The famous airplane factories near Kuibyshev, which were constructed by prisoners in extreme conditions in compressed time frames, played a significant role in the war with Nazi Germany, supplying the front with a large portion of its Soviet planes. Despite thematic differences, each of these three works analyzes the same phenomenon: the formation, development, and expansion of major production complexes under the direction of the People's Commissariat of Internal Affairs, later Ministry of Internal Affairs (NKVD-MVD USSR). (2) I am grateful to Liudmila Novikova, Victoria Frede, Paul Werth, and Rhiannon Dowling for their valuable comments and skillful translation. This article was prepared within the framework of a subsidy granted to the National Research University Higher School of Economics (HSE) by the government of the Russian Federation for the implementation of the Global Competitiveness Program. The authors examine two models of Gulag expansion: the first through camp colonization of distant and hard-to-reach parts of the country; and the second through the use of forced labor in populated regions of substantial economic value. …

Real-Time Adaptive Video Compression

Compressive sensing has been widely applied to problems in signal and imaging processing. In this work, we present an algorithm for predicting optimal real-time compression rates for video. The video data we consider is spatially compressed during the acquisition process, unlike in many of the standard methods. Rather than temporally compressing the frames at a fixed rate, our algorithm adaptively predicts the compression rate given the behavior of a few previous compressed frames. The algorithm uses polynomial fitting and simple filters, making it computationally feasible and easy to implement in hardware. Based on numerical simulations of real videos, the algorithm is able to capture object motion and approximate dynamics within the compressed frames. The adaptive video compression improves the quality of the reconstructed video (as compared to an equivalent fixed rate compression scheme) by several dB of peak signal-to-noise ratio without increasing the amount of information stored, as seen in numerical simulations presented here.

Fast spectroscopic imaging with pixel semiconductor detector Timepix and parallel data reading

Non-invasive techniques utilizing X-ray radiation offer a powerful tool for the inspection of the inner composition of a wide variety of objects. The highly sensitive hybrid semiconductor pixel detector Timepix is capable of detecting and resolving subtle and low-contrast differences in radiography measurements. Moreover the Timepix detector offers 65536 individual pixels with spectrometric capabilities. With proper per-pixel energy calibration this feature enables the application of various energy based imaging techniques - from basic energy windowing to fully spectroscopic imaging. The main limitations of these methods are the detector energy resolution and data acquisition speed of 100 frames per second - the necessity of taking frames with low occupancy for event by event cluster analysis leads to several hours long measurements. The latter nuisance can be overcome by the utilization of the newly developed modular read-out FITPix3 with the adapter chipboard designed for parallel data reading. This read-out version can acquire over 850 compressed frames per second which reduces the measurement time of many spectroscopic measurements by factor of ten (spectra with high enough statistics are taken in tens of minutes). The short description of the new FITPix3 parallel read-out together with the progression in spectroscopic multi-channel energy imaging demonstrated on model samples are presented in this contribution.

Wavelet based shock wave and muzzle blast classification for different supersonic projectiles

The article presents a pattern recognition approach to acoustic shock wave and muzzle blast detection. Gunshot signatures are divided into multiple classes, given by combination of 3 types of supersonic weapons of different caliber: 7.62mm, 5.56mm and 9mm and 3 types of acoustic events: shock wave, muzzle blast and reflections. The classification is performed on wavelet compressed 100μs time frames. The experiment shows that the choice of a fitting wavelet base is crucial for the quality of recognition.

Middle Stone Age technological organisation: lithic extraction at Swartkop Hill in the interior of Namaqualand, Northern Cape, South Africa

Heritage assessments commissioned by commercial mines within the broader ambit of South Africa's environmental and heritage legislative requirements have essentially driven archaeological research in Namaqualand. We demonstrate here how mitigation of heritage resources conducted according to specific imperatives and within compressed time frames is compatible with academic standards of research. A Middle Stone Age (MSA) quarry in Namaqualand was successfully mitigated prior to mining. Investigations at the inland locality of Swartkop Hill recorded extensive raw material extraction. Episodic procurement and knapping activities conducted at outcrops of metamorphosed chalcedonies resulted in high densities of lithics. Technological organisation took advantage of outcrops with quality toolstone while field processing reduced carrying loads. The assemblage probably dates to the southern African MSA 3 that falls within Marine Isotope Stage (MIS) 3 (~60 to 25 ka). Surprisingly high numbers of awls reflect functional considerations and the incipient development of a regional style.

P16.09: 3D inversion mode combined with STIC: a novel technique for fetal heart ventricle volume quantification

subjective scores obtained by five clinicians. Analysis of correlation was conducted using Pearson’s correlation coefficient. Results: The mathematical analysis of the videos showed significant correlation to the subjective analysis. The correlation coefficient was 0.59 for RMS (p = 0.01) and 0.51 for pixel difference algorithm (p = 0.03). The two objective methods of analyses were significantly correlated to each other, with correlation coefficient of 0.93 (p = 0.0002). However, RMS tended to show less variation, with the highest values just below 3% intensity error across the difference matrix, while pixel difference showed a range of quality ranks that varied from 0% difference between compressed and uncompressed frames to over 45% difference. This suggested that pixel difference may be a better differentiating algorithm. Conclusions: Both the RMS and pixel difference algorithms showed significant correlation to the subjective assessment of videoclip quality. Pixel difference may be a better differentiating algorithm to assess the difference of video quality after compression.

Benefits of rapid data assessment and visualization prove themselves in exploration scenarios

Use of mapping and visualization software is growing rapidly in exploration. Carmel Burns of Canadian company Geosoft, provider of geospatial solutions to earth science industries, describes how some of its customers are adapting to the possibilities. The ability to effectively display, rapidly assess and dynamically experiment with multiple datasets has helped to reduce risk and increase prospecting capabilities in exploration. Increasingly, what’s required in exploration is software that can handle large volumes of data and multiple data sources and data types, such as geophysical data, geochemical data, drillhole data, satellite imagery, GIS data and any kind of mapping data, within one single environment or transparently linked environments. Utilizing today’s visualization tools, geoscientists are able to reduce risk and increase understanding by looking at as much different data as they can, in as many different ways as they can, within compressed project time frames. Despite the fact that exploration companies are leaner, with fewer people and shorter project time frames, Dr Michal Ruder, principal of US-based Wintermoon Geotechnologies, says she has seen exponential improvements in productivity and data quality as a result of new software for mapping and visualization. Whereas it used to take weeks to process and interpret geoscience datasets, today it is not uncommon for geoscientists to address the salient issues of interpretations in the course of one or two days. ‘I can remember doing batch maps in paper copies back in the 1980s,’ says Dr Ruder. ‘Since then, the ability to image geoscientific datasets on a computer screen in realtime and continual improvements in visualization software have had an amazing impact on what we can do as geoscientists, and how quickly we can do it.’ Interpretation results are also more accurate because geoscientists have the tools to view the quality of the data in every single phase, from initial data processing and quality control through to visualization, integration and the final interpretations.

Object recognition in compressed imagery

Image-based applications can save time and space by operating on compressed data. The problem is that most mid- and high-level image operations, such as object recognition, are formulated as sequences of operations in the image domain. Such methods need direct access to pixel information as a starting point, but the pixel information in a compressed image stream is not immediately accessible. In this paper we show how to perform object recognition directly on compressed images (JPEG) and index frames from video streams (MPEG I-frames) without recovering explicit pixel information. The approach uses eigenvectors constructed from compressed image data. Our performance results show that a five-fold speedup can be gained by using compressed data.

The run probabilities of tes processes

The run statistics of a discrete-time, real-valued stochastic process are the statistics of process excursions above a given level. As such they are a special case of first passage times (hitting times) in discrete time. The study of run probabilities is motivated by applications such as compressed video, where a random and autocorrelated sequence of compressed frames arrives deterministically at a finite buffer, and the loss probability of consecutive frames (runs) constitutes a better measure of service quality than simple loss probabilities. This paper studies the run probabilities of a subclass of TES processes. A uniform TES process is a modulo-1 autoregressive stochastic process, uniform on [0,1); general TES processes are obtained by transforming a basic TES process to ones with general marginals. The paper develops an integral equation in the generating function of the run probabilities of TES processes. An exact matrix solution of theoretical interest is obtained, but the solution requires expens...

Developing managers for the learning organization

The learning organization makes new intellectual demands on managers. Managers are being asked not just to carry out their assigned tasks but to use the skills of analysis, interpretation and synthesis to help the organization learn its way out of the novel problems it increasingly faces in a time of rapid change. Traditional management development programs, however, send a contradictory message to learners when delivery is structured in a way that negates the reasoning capability of managers who are being encouraged by the organization to rely more heavily on their own reasoning. To facilitate organizational learning four fundamental changes in the way management development programs are designed are suggested; (1) situating learning in real work, (2) defining a less central role for experts, (3) spaced rather than compressed time frames, and (4) learning in community rather than individually. Examples of five management development programs which embody these elements are provided.

TES modeling for analysis of a video multiplexer

The transport of video images is likely to be a major application of high-speed networks of the future. These applications are capable of utilizing the high bandwidths that will become available with the advent of B-ISDN. In this paper, we propose a new methodology (called TES) for modeling the frame bitrate stream generated by compressed video sources. The main characteristic of this method is that it can model an arbitrary marginal distribution and approximate the autocorrelation structure of the random bitrate process generated by compressed frames. We present a modeling example utilizing this method, based on data from a video coding algorithm employing a layering technique. Using the source model, we develop a simulation model of a multiplexer of video sources. We show that this model can be used to address a number of design issues that arise in this class of problem. In particular, we show that for a layered video coding algorithm, it is possible to have a gain in the number of sources multiplexed at the cost of some loss of low priority packets.