High Compression Efficiency Research Articles

Multi-View Video Signal Processing Based on Disparity Estimation

Disparity estimation is used to eliminate redund ancy among different views in multiview video coding in order to obtain high compression efficiency. This paper proposes a reference viewpoint selection method based on the judgment principle of block feature vectors and similarities, which can reduce complexity and increase coding performance under the premise that the coding quality is ensured. Experimental results have demonstrated the effectiveness of this algorithm.

152 W average power Tm-doped fiber CPA system.

A high-power thulium (Tm)-doped fiber chirped-pulse amplification system emitting a record compressed average output power of 152 W and 4 MW peak power is demonstrated. This result is enabled by utilizing Tm-doped photonic crystal fibers with mode-field diameters of 35 μm, which mitigate detrimental nonlinearities, exhibit slope efficiencies of more than 50%, and allow for reaching a pump-power-limited average output power of 241 W. The high-compression efficiency has been achieved by using multilayer dielectric gratings with diffraction efficiencies higher than 98%.

Erbium Fiber Oscillator With an Intracavity Pulse Shaper for High-Energy Low-Pedestal Wavelength-Tunable Femtosecond Pulse Generation

An erbium fiber oscillator with dominating gain fiber length and an intracavity pulse shaper is experimentally demonstrated. The Kerr nonlinear phase shift induced in the fibers is suppressed by the pulse shaper, enabling high-energy (8.9 nJ) high-compression efficiency (93%) pulses of less than 270 fs duration (after linear dechirping) at modest (320 mW) pump power. A stably mode-locked spectrum corresponding to 19 nJ, 83 fs transform-limited pulse is achieved at 720 mW pump power. Wave-breaking-free pulse energy can be further enhanced by introducing stronger spectral phase modulation via the pulse shaper if more pump budget is available. We also demonstrate manipulation of the central wavelength and bandwidth of the output pulse by intracavity spectral amplitude modulation via the pulse shaper.

Information compression exploits patterns of genome composition to discriminate populations and highlight regions of evolutionary interest

BackgroundGenomic information allows population relatedness to be inferred and selected genes to be identified. Single nucleotide polymorphism microarray (SNP-chip) data, a proxy for genome composition, contains patterns in allele order and proportion. These patterns can be quantified by compression efficiency (CE). In principle, the composition of an entire genome can be represented by a CE number quantifying allele representation and order.ResultsWe applied a compression algorithm (DEFLATE) to genome-wide high-density SNP data from 4,155 human, 1,800 cattle, 1,222 sheep, 81 dogs and 49 mice samples. All human ethnic groups can be clustered by CE and the clusters recover phylogeography based on traditional fixation index (FST) analyses. CE analysis of other mammals results in segregation by breed or species, and is sensitive to admixture and past effective population size. This clustering is a consequence of individual patterns such as runs of homozygosity. Intriguingly, a related approach can also be used to identify genomic loci that show population-specific CE segregation. A high resolution CE ‘sliding window’ scan across the human genome, organised at the population level, revealed genes known to be under evolutionary pressure. These include SLC24A5 (European and Gujarati Indian skin pigmentation), HERC2 (European eye color), LCT (European and Maasai milk digestion) and EDAR (Asian hair thickness). We also identified a set of previously unidentified loci with high population-specific CE scores including the chromatin remodeler SCMH1 in Africans and EDA2R in Asians. Closer inspection reveals that these prioritised genomic regions do not correspond to simple runs of homozygosity but rather compositionally complex regions that are shared by many individuals of a given population. Unlike FST, CE analyses do not require ab initio population comparisons and are amenable to the hemizygous X chromosome.ConclusionsWe conclude with a discussion of the implications of CE for a complex systems science view of genome evolution. CE allows one to clearly visualise the evolution of individual genomes and populations through a formal, mathematically-rigorous information space. Overall, CE makes a set of biological predictions, some of which are unique and await functional validation.

Research on Spatial Statistical Data Compression Algorithm Based on Point Cloud Clustering

The spatial information service system have the characteristics of a large amount of massive data and a large number of users, so the compression algorithm for statistical data will affects the system performance of spatial data services. A compression algorithm for spatial statistical data based on point cloud clustering is proposed in this paper to solve the above-mentioned problems. The access rule of the spatial data will be mapped into a point cloud. And the part of points will be deleted according to the clustering gradient of point cloud. Then the statistical data is compressed by run-length coding and spatial clustering extraction. The experimental results show that the algorithm have a high compression efficiency.

Improved Compression Performance of H.264/MPEG4-AVC for Digital Video Using DVDP

Digital video sequences in uncompressed form require huge storage and high transmission bandwidth for multimedia communication. The increasing number of Video over Wireless (VoW) services is creating greater thrust for higher coding efficiency for digital video signals. Efficient coding and transmission control techniques are required to meet the needs of Quality of Service (QoS). H.264/MPEG4-advanced video coding (AVC) video enCOder/DECoder (CODEC) is the latest coding and compression standard from the International Telecommunications Union-Telecommunication (ITU-T). This standard is currently dominating the field by offering a flexible architecture and compression gain for video coding. Due to its high compression efficiency with low compression delay, it is used in many real time VoW transmission applications. Modern wireless networks provide many different means to adapt QoS like low end-to-end delay, efficient bandwidth-utilization and lower bit-rate. This paper presents a design of integrated CODEC scheme with relatively lower bit-rate and improved edge peak signal-to-noise ratio (EPSNR). Several important factors of video sequence are analyzed for achieving lower bit-rate. A new scheme is proposed at Application (APP) layer for video compression, called as Enhanced Intra Prediction (EnIP). This algorithm uses picture structure without B-pictures for real time VoW application. The proposed algorithm is implemented on TMS320DM6437; a multimedia processor, using Digital Video Development Platform (DVDP). The superior performance of the proposed EnIP algorithm is validated by experimental results. It shows that the implementation of EnIP using digital multimedia processor lowers the bit-rate and improves EPSNR significantly.

无人机侦察图像压缩

To reduce the storage space of image data and to recover the high quality image of an interested region,a method of segmented compression reconfiguration based on the interested region was proposed.Firstly,the Region of Interest(ROI)was extracted from the whole image according to some regularity of surveillance targets.The original image was then divided into ROI and Region of Background(BG)by using the segmentation algorithm.Finally,with the compression method based on wavelet transform,the ROI and BG region were compressed with different compression ratios by using the embedded coding of Set Partitioning in Hierarchical Trees(SPIHT).Simulation experiment shows that the method gives higher compression efficiency and the recovered image is more suitable for human eye under the same condition.Compared to other methods,this method increases the Peak Signal to Noise Ratio(PSNR)of image and solves the contradiction of the high compression ratio to high quality.

Relevant Window based Bitmap Compression in P2P Systems: Framework and Solution

P2P systems require neighbor peers to frequently exchange buffer-map (BM) messages for efficient content sharing and distribution, which, however, can result in considerable communication overhead. A big problem in the BMs exchanged between neighbor peers is that a lot of information in them is redundant. To reduce the redundancy, some P2P systems have adopted certain block-level compression schemes (e.g., Huffman encoding) to compress each BM in isolation. However, these schemes simply treat each BM separately and as a single block of data, which largely affects their compression efficiency. In this paper, we propose a novel relevant-window-based (RW) compression framework, which takes advantage of the correlation between sequentially exchanged BMs between neighbor peers and thus can greatly remove the redundancy in them. We accordingly design a RW-based distributed compression scheme, which can work alone or co-work well with an existing block-level compression scheme for higher compression efficiency. We prove the correctness of our scheme and derive tight upper bound on average length of compressed bitmaps by our scheme via mathematical modeling. Numerical results demonstrate that our scheme alone can achieve compression efficiency of 96.6%, which can be further increased to up to 97.1% when jointly working with a block-level compression scheme.

Flexible Mode Selection and Complexity Allocation in High Efficiency Video Coding

To improve compression performance, High Efficiency Video Coding (HEVC) employs a quad-tree based block representation, namely Coding Tree Unit (CTU), which can support larger partitions and more coding modes than a traditional macroblock. Despite its high compression efficiency, the number of combinations of coding modes increases dramatically, which results in high computational complexity at the encoder. Here we propose a flexible framework for HEVC coding mode selection, with a user-defined global complexity factor. Based on linear programming, a hierarchical complexity allocation scheme is developed to allocate computational complexities among frames and Coding Units (CUs) to maximize the overall Rate-Distortion (RD) performance. In each CU, with the allocated complexity factor, a mode mapping based approach is employed for coding mode selection. Extensive experiments demonstrate that, with a series of global complexity factors, the proposed model can achieve good trade-offs between computational complexity and RD performance.

Joint Rate Allocation of Stereoscopic 3D Videos in Next-Generation Broadcast Applications

3D video is foreseen to be the next natural step in the evolution of digital media. Among various representation formats available for 3D videos, stereoscopic is considered the most mature technology so far. This paper proposes a joint rate allocation scheme for next-generation broadcast applications, in which multiple stereoscopic 3D videos are encoded and transmitted simultaneously. We first propose a scalable stereoscopic video coding scheme that inherits features from scalable video coding. The scalable format makes the rate control of each video as easy as bit-stream extraction. For the two views in stereo videos, the reference view is independently coded to provide backward compatibility, while the auxiliary view is coded using the reference view as a base layer to remove inter-view redundancy. Based on the well-known fact that the human visual system can compensate and conceal the degraded fidelity in one of the two views, provided the other view is encoded at a high quality, the proposed joint rate allocation scheme does adaptive bit allocation between views to obtain high compression efficiency and better quality. Experimental results show that the proposed framework achieves smaller quality fluctuation among videos and higher perceived quality in each video as compared with the existing system.

Fast directional search algorithm for fractional pixel motion estimation for H.264 AVC

Fractional pixel motion estimation (ME) is required to achieve more accurate motion vectors and higher compression efficiency. This results in an increase in the computational complexity of the ME process because of additional computational overheads such as interpolation and fractional pixel search. Fast algorithms for fractional ME in H.264/AVC are presented. To reduce the complexity of fractional pixel ME, unimodal error surface assumption is used to check only some points in the fractional pixel search window. The proposed algorithm employs motion prediction, directional quadrant and point-based search pattern and early termination to speed up the process. Hence, the proposed algorithm efficiently explores the neighborhood of integer pixel based on high correlation that exists between the neighboring fractional pixels and unimodal property of error surface. The proposed search pattern and early termination reduce computational time by almost 8% to 18% as compared to the hierarchical fractional pixel algorithm employed in the reference software with a negligible degradation in video quality and negligible increase in bit rate.

Renovation in Compression Expertness of Huffman Coding and Intelligent Data Encryption

Data compression is used for reducing storage requirements. It involves transforming data of a given format, called source message, to data of a smaller sized format, called compressed message. The Data compression helps in reducing the size of the database so that it is very easy to maintain huge database. On the other hand Type Casting is used to convert the input source message into suitable format so that Huffman Algorithm can work on maximum data formats and after that Data Normalization technique is used to remove redundancy from the data this technique enhance the compression efficiency of Huffman Algorithm. Decreasing the amount of data required representing a source of information while preserving the original content as much as possible and after that providing security to this compressed code word with the application of data encryption. The main objectives of this paper are to get higher compression efficiency by applying a planned technique on Huffman Algorithm and providing security to this compressed data to limit the unauthorized access using data encryption.

High Efficiency 3D Video Coding Using New Tools Based on View Synthesis

We propose a new coding technology for 3D video represented by multiple views and the respective depth maps. The proposed technology is demonstrated as an extension of the recently developed high efficiency video coding (HEVC). One base views are compressed into a standard bitstream (like in HEVC). The remaining views and the depth maps are compressed using new coding tools that mostly rely on view synthesis. In the decoder, those views and the depth maps are derived via synthesis in the 3D space from the decoded baseview and from data corresponding to small disoccluded regions. The shapes and locations of those disoccluded regions can be derived by the decoder without any side information transmitted. To achieve high compression efficiency, we propose several new tools such as depth-based motion prediction, joint high frequency layer coding, consistent depth representation, and nonlinear depth representation. The experiments show high compression efficiency of the proposed technology. The bitrate needed for transmission of two side views with depth maps is mostly less than 50% than that of the bitrate for a single-view video.

Depth-based coding of MVD data for 3D video extension of H.264/AVC

This paper describes a novel approach of using depth information for advanced coding of associated video data in Multiview Video plus Depth (MVD)-based 3D video systems. As a possible implementation of this conception, we describe two coding tools that have been developed for H.264/AVC based 3D Video Codec as response to Moving Picture Experts Group (MPEG) Call for Proposals (CfP). These tools are Depth-based Motion Vector Prediction (DMVP) and Backward View Synthesis Prediction (BVSP). Simulation results conducted under JCT-3V/MPEG 3DV Common Test Conditions show, that proposed in this paper tools reduce bit rate of coded video data by 15% of average delta bit rate reduction, which results in 13% of bit rate savings on total for the MVD data over the state-of-the-art MVC+D coding.Moreover, presented in this paper conception of depth-based coding of video has been further developed by MPEG 3DV and JCT-3V and this work resulted in even higher compression efficiency, bringing about 20% of delta bit rate reduction on total for coded MVD data over the reference MVC+D coding. Considering significant gains, proposed in this paper coding approach can be beneficial for development of new 3D video coding standards.

GIS 벡터맵 데이터 압축을 위한 혼합형 폴리라인 단순화

본 논문은 혼합형 폴리라인 단순화와 공간 에너지 집중을 이용한 GIS 벡터맵 데이터 압축을 제안한다. 제안한 방법에서는 GIS 벡터맵에서 폴리라인 속성을 가지는 레이어들에 대해, 최소 면적 오차 기반의 혼합형 폴리라인 단순화 및 공간 에너지 집중에 의하여 선택된 레이어 내의 폴리라인 데이터들을 압축한다. 제안한 단순화 및 공간 에너지 집중는 폴리라인의 형상을 유지하면서 데이터 압축 효과를 향상시킨다. 가시적 화질과 압축률을 통한 평가 결과로부터 제안한 방법이 기존 방법보다 우수한 화질과 높은 압축률을 보임을 확인하였다. This paper presents a GIS vector map data compression scheme based on hybrid polyline simplification method and SEC(spatial energy compaction). The proposed method extracts all layers which contain polylines in the GIS vector map and compress all polylines in extracted layers by the hybrid polyline simplification and SEC based on MAE(minimum area error) for each segment in the line. The proposed simplification and SEC increase the compression ratio while preserving the shape quality. We analyze the visual aspects and compression efficiency between the original GIS vector map and the compressed map. From experimental results, we verify that our method has the higher compression efficiency and visual quality than conventional methods.

Development of sap compressing systems from oil palm trunk

In an attempt to utilize felled palm trunks, we found that they contain a large quantity of sap, and that abundant glucose and other fermentable sugars exist in the sap. In this study, we developed a prototype system for compressing the sap from oil palm trunks; it is composed of a rotary lathe, a shredder, and a compressing mill. A high compression efficiency of the mill was maintained (a sap recovery of ∼80%) by properly preparing the trunks, which included peeling the bark and the outer layer of the trunks. In addition, a higher compression efficiency was obtained with a relatively slow rotation of the mill. Consequently, the net energy ratio (NER) reached 4.8 when the sugar concentration in the sap was 79 kg m−3. This is the first paper about new developed systems for sap compressed from oil palm trunk.

Performance analysis of secured video transmission over 3G networks based on H.264/AVC

Video transmission in wireless environment is a challenging task calling for high-compression efficiency as well as network friendly design which is achieved by means of H.264/AVC. Video transmission for mobile terminals is a major application in 3G systems and is a key factor for its success. Wireless links are error-prone and unreliable and so video transmission over 3G networks experiences packet loss due to fading and interference causing substantial quality degradation to the video which may be avoided by appropriate error resilience features. Moreover, it is important that the video is transmitted in a secured manner in certain applications like video conferencing, medical applications etc. This is achieved with the help of suitable encryption techniques without affecting the quality of the decoded video. Encryption of video transmission in wireless environment with suitable error resilience techniques to achieve good quality is the main objective of this work. Performance analysis of secured video ...

영상저장장치(DVR)디자인 개발을 위한 제품 분석

This study is a research development case study on the free-standing Network based camera video recording DVR. The DVR devices till now have recorded data by converting and compressing analogue video to digital, but in the future, digital videos will be recorded directly through the network camera. Also, digital compressing methods are progressing from MPEG-4, MJPEG, to H.264 method, with products considering high definition compression efficiency, minimized data size, network compatibility, and fast pending time. According to this, in 2012, it is predicted that network camera and video devices throughout the world will outrun the current analogue devices. With this transition of technological environment and fast product pending speed, a new, quality focused design is required for product development including technical realization, reliability, high-definition, compression technology, will be essential. Manufacturers are researching a new direction for the product appearance. This study considers the actual end-users as the design target and through consumer survey on preferences, design needs and required elements necessary in the design development process are extracted. Furthermore, usability and preferred images were explored through literature study and market research. Through this research process, appropriate forms for the network based DVR were analyzed, and applied into the design development process. This product will take into consideration its competitiveness and the significance of USP(Unique Selling Proposition) which is the design supremacy and professional technical skills.

Fast subpel motion estimation for H.264/advanced video coding with an adaptive motion vector accuracy decision

The quarter-pel motion vector accuracy supported by H.264/advanced video coding (AVC) in motion estimation (ME) and compensation (MC) provides high compression efficiency. However, it also increases the computational complexity. While various well-known fast integer-pel ME methods are already available, lack of a good, fast subpel ME method results in problems associated with relatively high computational complexity. This paper presents one way of solving the complexity problem of subpel ME by making adaptive motion vector (MV) accuracy decisions in inter-mode selection. The proposed MV accuracy decision is made using inter-mode selection of a macroblock with two decision criteria. Pixels are classified as stationary (and/or homogeneous) or nonstationary (and/or nonhomogeneous). In order to avoid unnecessary interpolation and processing, a proper subpel ME level is chosen among four different combinations, each of which has a different MV accuracy and number of subpel ME iterations based on the classification. Simulation results using an open source x264 software encoder show that without any noticeable degradation (by −0.07 dB on average), the proposed method reduces total encoding time and subpel ME time, respectively, by 51.78% and by 76.49% on average, as compared to the conventional full-pel pixel search.

The variable-interval arithmetic coding using asymptotic deterministic randomness for data compression and encryption

Different from the traditional way which compresses the data first and then encrypts the compressed bit-stream later, a novel compression and encryption scheme using variable model arithmetic coding and coupled chaotic system can encrypt and compress the input plaintext synchronously. However, there will be a compromise between the amount of compression achieved and the amount of security incorporated, because the compression efficiency is determined by the key bit-stream. In this paper, an improved scheme using variable-interval arithmetic coding and asymptotic deterministic randomness has been proposed. The improved scheme is secure because the key bit-stream generated by the asymptotic deterministic randomness can resist previous attacks against chaotic encryption. In addition, the compression efficiency will not change with the key bit-stream, because the statistical model will no longer be changed. The results show that the new scheme can achieve high security and compression efficiency.