Code Stream Research Articles

Prediction Truncation Algorithm Based on Regression Analysis for Embedded Block Coding

In order to solve the problems of execution complexity and time waste in compression process induced by Post Compression Rate Distortion(PCRD) Optimization in embedded block coding in JPEG2000, this paper proposes an effective method to promote coding efficiency-embedded block coding algorithm with prediction truncation based on regression analysis. This algorithm predicts the truncation points based on regression formula derived from linear regression analysis. It avoids scanning and encoding the bit planes that can be truncated, discards the time-consuming rate-distortion truncation processing, so that the algorithm is able to speed up the compression process. The experiment results show the algorithm obtains obvious promotion efficiency of coding speed. high compression ratio such as 0.125 or 0.0625, the majority of the coefficients which have been encoded in tier-2 stage are discarded through truncation. Obviously, a lot of running time is wasted in the coding of coefficient bits that will be truncated. This paper proposes the predict truncation algorithm based on regression analysis, while embedded coding it can predict plane scan code stream position of the truncated points, give up coding to the coefficients bits that will be discarded, and give up the rate distortion calculation and optimization truncation based on cycle search in Tier-2 coding, thus greatly improves the encoding speed.

METHOD OF RECONSTRUCTION OF THE FRAME STREAM WITH THE SETTING INTEGRITY LEVEL OF THE VIDEO INFORMATION

It is shown that the key access method on getting video information in dynamic regime is based on the use of remote means of collection and access to information resources. It is proved that the reduction of compressed video bit rate is achieved by significantly reducing the integrity of the video and increase its processing delays. It is states the developing a method of reconstruction of the video stream based on: identification levels of the hierarchical structure of the compressed code stream; encapsulation and decoding biadic codes of basic elements interframe aperture of P-frames package; approximation interframe apertures on its basic elements; assembling P-frames with individual inter apertures; restoring the original frames using information on the base frame and matrix signs. It is proved that the technology created by processing video is unique and can realy reduce the amount of distortion introduced by comparison with the technology based on MPEG standard, which ultimately increases the integrity of video information resource.

Content-aware optimization on rate-distortion and network traffic for scalable video multicast networks

This paper aims to optimize the content-aware prioritization of scalable video multicast, which is coupled with multipath streaming and network coding based routing. It constructs multiple layer distribution meshes for the scalable video stream to minimize the total video distortion at all the receivers, determines the base layer meshes with minimum costs to maintain application-layer QoS and the layer synchronization of SVC streaming, and improves the network throughput by encouraging path-overlapping transmissions and thus allowing bandwidth sharing among different receivers for the same video layer by utilizing network coding. The targeted problem is formulated into a minimization programming in which the quality variation between layers, the transmission cost of the base layer, as well as the efficient resource utilization are jointly considered. By decomposition and dual approach, the global convex problem is solved by a two-level decentralized iterative algorithm. The implementation of the distributed algorithm is discussed with regard to the communication overhead, and the convergence performance is validated by numerical experiments. Packet-level simulations demonstrate that the proposed algorithm could approximately achieve the maximum flow rates determined by Max-Flow Min-Cut Theorem and benefit the overall received video quality.

Two-Level Secret Key Image Encryption Method Based on Piecewise Linear Map and Logistic Map

Some chaos-based image encryption schemes using plain-images independent secret code streams have weak encryption security and are vulnerable to chosen plaintext and chosen cipher-text attacks. This paper proposed a two-level secret key image encryption method, where the first-level secret key is the private symmetric secret key, and the second-level secret key is derived from both the first-level secret key and the plain image by iterating piecewise linear map and Logistic map. Even though the first-level key is identical, the different plain images will produce different second-level secret keys and different secret code streams. The results show that the proposed has high encryption speed, and also can effectively resist chosen/known plaintext attacks.

Plaintext Related Two-level Secret Key Image Encryption Scheme

Some chaos-based image encryption schemes using plain-images independent secret code streams have weak encryption security and are vulnerable to chosen plaintext and chosen cipher-text attacks. This paper proposed a two-level secret key image encryption scheme, where the first-level secret key is the private symmetric secret key, and the second-level secret key is derived from both the first-level secret key and the plain image by iterating piecewise linear map and Logistic map. Even though the first-level key is identical, the different plain images will produce different second-level secret keys and different secret code streams. The results show that the proposed has high encryption speed, and also can effectively resist the existing cryptanalytic attacks. DOI: http://dx.doi.org/10.11591/telkomnika.v10i6.1599 Full Text: PDF

Efficient rate control approach for JPEG2000 image coding

Abstract. JPEG2000, the new image coding standard, is more effi-cient when compared with the old JPEG standard. However, most ofthe computationsand memory usagein post-compressionrate distor-tion(PCRD)optimizationschemeinJPEG2000isredundant.Wepro-pose an efficient rate control approach for the JPEG2000 encoder. Inthis approach, optimal rate distortion (RD) slope threshold is selectedusing the minimum RD slope of lower level horizontally and verticallylow pass (LL 0 ) subband of the wavelet decomposed image. Also, thepasses of the code blocks of other subbands, whose RD slopes areless than the optimal RD slope, are skipped. The proposed approachreduces memory requirements and encoding time when comparedwith the existing rate control approaches for JPEG2000 standard,and also provides the same image quality as that of the PCRDapproach used in the JPEG2000 standard. © 2012 SPIE andIS&T. [DOI: 10.1117/1.JEI.21.3.033004] 1 IntroductionJPEG2000 is the new state-of-art image and video codingstandard. It has excellent coding performance and novel fea-tures such as superior low-bit rate compression performance,lossless and lossy compression, progressive transmission,region of interest coding, error resilience and randomcode stream access, and so on.

수질모델링 지원을 위한 GIS 기반 한국형 Reach File 설계

수질모델링에 필요한 다양한 입력데이터는 관련 정보의 확보방안 및 표준화가 되어 있지 않아 수질모델링 결과 및 수질분석에 많은 영향을 주고 있다. 이에 본 연구에서는 효율적인 수질 모델링을 위해 정확한 수리 수문 데이터를 기반으로 한 수질모델링의 기초자료 데이터베이스인 한국형 Reach File을 설계하였다. 한국형 Reach File은 동일한 수리학적 특색을 가지는 구간(Reach)에 대한위치정보 기반의 수리학 데이터베이스로써, 각 구간을 대표할 수있는 Reach 코드와 Catalog Unit, Segment, Marker Index의 위상정보를 갖고 있으며 하천명이나 하천코드와 같은 기존 코드와의 연계를 고려하여 설계되었다. 설계방안을 토대로 경기도 광주시의 경안천을 대상으로 시범 구축을 통하여 본 설계안을 검토한 결과, 수질모델링에 필요한 기초데이터를 하나의 기준으로 체계화하여 하천정보를 데이터베이스화하고 기 구축 데이터베이스와의 연계 및 활용방안도 마련할 수 있었다. 또한, 각 구간별로 정의된 Reach 코드를 이용하여 수질기초시설, 오염원데이터, 관리기관 등 기존 데이터베이스와 연계를 통해 보다 체계적인 수질의 관리가 가능함을 알 수 있었다. 향후 연구에서는 Reach 코드를 하천공간데이터의 국가표준데이터로 선정할 수 있도록 하천 정보 표준화에 관한 연구가 필요하며, 전국 모든 하천에 Reach 코드를 부여하여 보다 많은 데이터베이스와의 연계할 수 있는 방안을 마련해야 할 것이다. Various input data required for water quality modeling have considerable impacts on modeling results and relevant analysis due to the absence of data standardization and lack of data accuracy. With this in mind, this study mainly focused on the designing Korean Reach File for more effective water quality modeling through the supply of database composed with accurate hydraulic and hydrologic data. The Korean Reach File is the hydraulic database with the locational information of individual reaches, and each reach represents the stream reach of homogeneous hydraulic characteristics. In detail, it has reach code designating each stream reach, and topological information including catalog unit, segment, marker and index. It was also designed considering linkage of existing codes such as stream name and stream code. The devised reach code was implemented to Kyungan River at the City of Gwangju of Kyunggi Province and the results showed that the reach code could effectively support the input database integrating basic numerous data required for water quality modeling based on a criterion as well as easier linkage and utilization with existing database. In addition, more systematic water quality management was enabled through the linkage of existing data such as treatment facilities, pollutant data, and management institutes using the reach codes defined for each stream section. In the future, more efforts need to be made to adopt the reach code as the national standard data thereby enabling utilization of numerous relevant database through the assigning of reach code to individual stream reaches nationwide.

Prediction Truncation Algorithm Based on Regression Analysis for Embedded Block Coding

In order to solve the problems of execution complexity and time waste in compression process induced by Post Compression Rate Distortion(PCRD) Optimization in embedded block coding in JPEG2000, this paper proposes an effective method to promote coding efficiency-embedded block coding algorithm with prediction truncation based on regression analysis. This algorithm predicts the truncation points based on regression formula derived from linear regression analysis. It avoids scanning and encoding the bit planes that can be truncated, discards the time-consuming rate-distortion truncation processing, so that the algorithm is able to speed up the compression process. The experiment results show the algorithm obtains obvious promotion efficiency of coding speed. high compression ratio such as 0.125 or 0.0625, the majority of the coefficients which have been encoded in tier-2 stage are discarded through truncation. Obviously, a lot of running time is wasted in the coding of coefficient bits that will be truncated. This paper proposes the predict truncation algorithm based on regression analysis, while embedded coding it can predict plane scan code stream position of the truncated points, give up coding to the coefficients bits that will be discarded, and give up the rate distortion calculation and optimization truncation based on cycle search in Tier-2 coding, thus greatly improves the encoding speed.

Adaptive Binary Arithmetic Coder‐Based Image Feature and Segmentation in the Compressed Domain

Image compression is necessary in various applications, especially for efficient transmission over a band‐limited channel. It is thus desirable to be able to segment an image in the compressed domain directly such that the burden of decompressing computation can be avoided. Motivated by the adaptive binary arithmetic coder (MQ coder) of JPEG2000, we propose an efficient scheme to segment the feature vectors that are extracted from the code stream of an image. We modify the Compression‐based Texture Merging (CTM) algorithm to alleviate the influence of overmerging problem by making use of the rate distortion information. Experimental results show that the MQ coder‐based image segmentation is preferable in terms of the boundary displacement error (BDE) measure. It has the advantage of saving computational cost as the segmentation results even at low rates of bits per pixel (bpp) are satisfactory.

Multiple description coding of scalable video stream based on unequal loss protection and optimal rate allocation

Forward Error Correction (FEC) codes may be used to protect a video code stream against packet erasures or errors when passing through an error-prone network. To have maximum possible fidelity at the decoder side, an Unequal Loss Protection (ULP) approach should be used to packetize the scalable video code stream, so that the different parts of the scalable video stream are protected according to their importance. Unequal loss-protected packetization leads to segmentation of the scalable code stream, such that the source can be reconstructed with the maximum possible fidelity at the decoder side. In Ardestani et al. (2009) [1] we have found an analytical relation between the optimal sizes of any two consecutive segments. This idea yields an efficient (as efficient as the local search algorithm in Stankovic et al. (2002) [2]) low-complexity progressive solution for the segmentation problem. In this paper, we use a progressive approach for ULP packetization of a scalable video stream generated from a T+2D encoder. In addition, an optimal rate allocation is used for optimal rate budget division between successive Groups Of Pictures (GOPs) of the video sequence. The experimental results demonstrate that the optimal rate budget allocation outperforms the conventional strategy of equal rate budget distribution up to 0.65 dB.

Impact of Variable Length Codes on the Interleaving Gain of Turbo Systems: The Concept of Bounded Spectrum

When a telecommunication system is constrained in terms of delay and complexity, it is usually wise to allow some cross-layer cooperation between the source and channel layers. In this context, the success of joint source-channel turbo techniques has been attested several times in the literature, in particular to transmit variable length code (VLC) streams which are very sensitive to error propagation. Capitalizing on previously developed performance upper bounds, this paper investigates whether the VLC can contribute to the interleaving gain of concatenated codes just as a convolutional code with non-catastrophic encoder would. To this end, the important concept of bounded VLC spectrum is introduced and is proved to be a sufficient condition for the VLC to contribute indeed to the interleaving gain. This concept is also proved to be closely related to non-catastrophic VLCs and, under certain assumptions, to the well known concept of statistically synchronizable VLCs.

Work Piece Length Measure System Based on Image

Corporation work piece length measure system based on digital image processing technology. CCD vidicon is used as the image capture equipment. Image signal are converted into 8 bits digital code stream by CMOS image sensor chip OV9650. DSP chip of TI is used as the core of image processing in the scheme. Peripheral SDRAM are expanded through peripheral bus to save the large amounts of temporary data in data processing to reduce the time for image processing. Median filtering is adopted in image enhance of the object image. The length of rectangle work piece can be measured in the distance by untouched way by improved edge recognition algorithm in real time. The measurement result is displayed by LCD. Meanwhile the measure system communicates with PC through communication interface. It has been proved that the system can guarantee real-time and high accurate. It’s a typical instance of DSP and digital image processing technology used in industry.

Lossless and lossy coding for multispectral image based on sRGB standard and residual components

In this paper, we present a multispectral image (MSI) compression method using a lossless and lossy coding scheme, which focuses on the seamless coding of the RGB bit stream to enhance the usability of the MSI. The proposed method divides the MSI data into two components: RGB and residual. The RGB component is extracted from the MSI by using the XYZ color matching functions, a color conversion matrix, and a gamma curve. The original MSI is estimated by an RGB data encoder and the difference between the original and the estimated MSI, which is referred to as the residual component in this paper. Next, the RGB and residual components are encoded by using JPEG2000, and progressive decoding is achieved from the losslessly encoded code stream. Experimental results show that a high-quality RGB image can be obtained at a low bit rate with primary encoding of the RGB component. In addition, by using the proposed method, the quality of a spectrum can be improved by decoding the residual data, and the quality is comparable to that obtained by using JPEG2000. The lossless compression ratio obtained by using this method is also similar to that obtained by using JPEG2000 with the integer Karhunen-Loeve transform.

No-reference analysis of decoded MPEG images for PSNR estimation and post-processing

We propose no-reference analysis and processing of DCT (Discrete Cosine Transform) coded images based on estimation of selected MPEG parameters from the decoded video. The goal is to assess MPEG video quality and perform post-processing without access to neither the original stream nor the code stream. Solutions are presented for MPEG-2 video. A method to estimate the quantization parameters of DCT coded images and MPEG I-frames at the macro-block level is presented. The results of this analysis is used for deblocking and deringing artifact reduction and no-reference PSNR estimation without code stream access. An adaptive deringing method using texture classification is presented. On the test set, the quantization parameters in MPEG-2 I-frames are estimated with an overall accuracy of 99.9% and the PSNR is estimated with an overall average error of 0.3 dB. The deringing and deblocking algorithms yield improvements of 0.3 dB on the MPEG-2 decoded test sequences.

Texture segmentation in the joint photographic expert group 2000 domain

Image segmentation is an important task in many image processing systems. For efficient transmission over a band-limited channel, original images are often compressed before being stored in databases. In order to avoid the burden of decompressing an image, it is desirable to extract features directly from a code stream. This approach saves computational time significantly. The look up table used for the MQ coder defined in joint photographic expert group 2000 (JPEG2000) called the MQ table provides probability models for bit-plane coding of wavelet coefficients, the wavelet histogram information can be obtained directly from a JPEG2000 code stream. Thus, the MQ feature based on the MQ table is proposed to segment an image in the JPEG2000 domain directly. Experimental results of clustering these features by using the simple K-means algorithm show the potential of MQ feature.

Change detection in JPEG 2000 compressed video

A method for detecting scene changes from JPEG 2000 compressed images is presented. Change information and localisation is derived from changes in the local data rate. They can be extracted by analysing the code streams only. The computationally expensive decoding of image data is eliminated.

Optimal Puncturing Ratios and Energy Allocation for Multiple Parallel Concatenated Codes

We propose a systematic design framework for optimal, low-complexity punctured multiple parallel concatenated codes (MPCCs), based on minimizing the convergence threshold using extrinsic information transfer (EXIT) charts. As the convergence threshold is related to the area between the two EXIT curves, the corresponding optimization problem is equivalent to a curve-fitting problem. The EXIT curves are determined by the respective EXIT functions of the constituents, which can be conveniently shaped through the use of random puncturing and unequal energy allocations across parallel coding streams. The design task is therefore to find the optimal combination of constituents, puncturing ratios, and energy allocation for matching the EXIT curves. A search over all rate-one convolutional codes of memory length four or less is performed, identifying 98 classes of codes with unique EXIT functions out of a total of 310 codes. Low-complexity MPCCs with up to four constituents are found, where the convergence thresholds are observed to be within 0.1 dB or less of the fundamental minimum signal-to-noise ratio (SNR) corresponding to the binary phase-shift keying (BPSK) capacity for code rates 1/3 les R les 7/8. Further allowing for unequal energy allocation, the convergence thresholds for lower code rates are similarly improved.

3D Color Set Partitioning in Hierarchical Trees

This paper introduces the 3D color set partitioning in hierarchical trees (3D-CSPIHT) low bit rate embedded video coding scheme. The codec exploits the correlation between temporal and spatial wavelet coefficients and the interdependency between luminance and chrominance components to code color video sequences without the need for explicit bit allocation. Besides offering rate scalability, the new codec also produces multi-resolution scalable code streams. The hierarchical variable size block matching motion estimation technique is also integrated to demonstrate the motion estimation option with 3D-CSPIHT. The coding results show that 3D-CSPIHT produces better performance and visual quality compared to 3D-SPIHT.

Patterns of convergence in rat zona incerta from the trigeminal nuclear complex: light and electron microscopic study.

In contrast to the restricted receptive field (RF) properties of the ventral posteromedial nucleus (VPM), neurons of the ventral thalamus zona incerta (ZI) have been shown to exhibit multiwhisker responses that vary from the ventral (ZIv) to the dorsal (ZId) subdivision. Differences in activity may arise from the trigeminal nuclear complex (TNC) and result from subnucleus specific inputs via certain cells of origin, axon distribution patterns, fiber densities, bouton sizes, or postsynaptic contact sites. We tested this hypothesis by assessing circuit relationships among TNC, ZI, and VPM. Results from tracer studies show that, 1) relative to ZId, the trigeminal projection to ZIv is denser and arises predominantly from the principalis (PrV) and interpolaris (SpVi) subdivisions; 2) the incertal projection from TNC subnuclei overlaps and covers most of ZIv; 3) two sets of PrV axons terminate in ZI: a major subtype, possessing bouton-like swellings, and a few fine fibers, with minimal specialization; 4) both PrV and SpVi terminals exhibit asymmetric endings and preferentially target dendrites of ZI neurons; 5) small and large neurons in PrV are labeled after retrograde injections into ZI; 6) small PrV cells with incertal projections form a population that is distinct from those projecting to VPM; and 7) approximately 30-50% of large cells in PrV send collaterals to ZI and VPM. These findings suggest that, 1) although information to ZI and VPM is essentially routed along separate TNC circuits, streams of somatosensory code converge in ZI to establish large RFs, and 2) subregional differences in ZI response profiles are attributable in part to TNC innervation density.

Ordering of diagnostic information in encoded medical images. Accuracy progression

AbstractA concept of diagnostic accuracy progression for embedded coding of medical images was presented. Implementation of JPEG2000 encoder with a modified PCRD optimization algorithm was realized and initially verified as a tool for accurate medical image streaming. Mean square error as a distortion measure was replaced by other numerical measures to revise quality progression according to diagnostic importance of successively encoded image information. A faster increment of image diagnostic importance during reconstruction of initial packets of code stream was reached. Modified Jasper code was initially tested on a set of mammograms containing clusters of microcalcifications and malignant masses, and other radiograms. Teleradiologic applications were considered as the first area of interests.