• Title/Summary/Keyword: B frame coding

Search Result 149, Processing Time 0.025 seconds

Performance Analysis of STTC Using Time Space Coding Method Appropriate for OFDM System (OFDM System에서 시공간 부호기법으로 STTC의 성능분석)

  • 김동옥
    • Proceedings of the IEEK Conference
    • /
    • 2003.07a
    • /
    • pp.473-476
    • /
    • 2003
  • In this paper, presents a way to maximize transmission efficiency and reception ability through transmission diversity technology, which can be adapted to wireless multimedia OFDM system. The presented method is a comparative analysis between a case where parameter a for time average is 0.3, 1 with consideration of channel presumption with two types of rms delayed proliferation, which is 50nsec, 150nsec, for the performance analysis of STTC(Space-Time Trellis Code) using time-space code method appropriate for MIMO channel, and performance in the case where presumed channel value from long training column section is applied to according frame in a single frame. The result showed that BER brought SNR improvement of 1.0dB in 10$^{-3}$ when a was 0.3 than using only the long training column, and showed increase of general performance improvement for the sake of time average rather than the case without.

  • PDF

Fuzzy Logic Based Temporal Error Concealment for H.264 Video

  • Lee, Pei-Jun;Lin, Ming-Long
    • ETRI Journal
    • /
    • v.28 no.5
    • /
    • pp.574-582
    • /
    • 2006
  • In this paper, a new error concealment algorithm is proposed for the H.264 standard. The algorithm consists of two processes. The first process uses a fuzzy logic method to select the size type of lost blocks. The motion vector of a lost block is calculated from the current frame, if the motion vectors of the neighboring blocks surrounding the lost block are discontinuous. Otherwise, the size type of the lost block can be determined from the preceding frame. The second process is an error concealment algorithm via a proposed adapted multiple-reference-frames selection for finding the lost motion vector. The adapted multiple-reference-frames selection is based on the motion estimation analysis of H.264 coding so that the number of searched frames can be reduced. Therefore the most accurate mode of the lost block can be determined with much less computation time in the selection of the lost motion vector. Experimental results show that the proposed algorithm achieves from 0.5 to 4.52 dB improvement when compared to the method in VM 9.0.

  • PDF

Parametric Video Compression Based on Panoramic Image Modeling (파노라믹 영상 모델에 근거한 파라메트릭 비디오 압축)

  • Sim Dong-Gyu
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.43 no.4 s.310
    • /
    • pp.96-107
    • /
    • 2006
  • In this paper, a low bitrate video coding method based on new panoramic modeling is proposed for panning cameras. An input video frame from a panning camera is decomposed into a background image, rectangular moving object regions, and a residual image. In coding the background, we employ a panoramic model that can account for several image formation processes, such as perspective projection, lens distortion, vignetting and illumination effects. Moving objects aredetected, and their minimum bounding rectangular regions are coded with a JPEG-2000 coder. We have evaluated the effectiveness of the proposed algorithm with several indoor and outdoor sequences and found that the PSNR is improved by $1.3{\sim}4.4dB$ compared to that of JPEG-2000.

Improved AR-FGS Coding Scheme for Scalable Video Coding (확장형 비디오 부호화(SVC)의 AR-FGS 기법에 대한 부호화 성능 개선 기법)

  • Seo, Kwang-Deok;Jung, Soon-Heung;Kim, Jin-Soo;Kim, Jae-Gon
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.31 no.12C
    • /
    • pp.1173-1183
    • /
    • 2006
  • In this paper, we propose an efficient method for improving visual quality of AR-FGS (Adaptive Reference FGS) which is adopted as a key scheme for SVC (Scalable Video Coding) or H.264 scalable extension. The standard FGS (Fine Granularity Scalability) adopts AR-FGS that introduces temporal prediction into FGS layer by using a high quality reference signal which is constructed by the weighted average between the base layer reconstructed imageand enhancement reference to improve the coding efficiency in the FGS layer. However, when the enhancement stream is truncated at certain bitstream position in transmission, the rest of the data of the FGS layer will not be available at the FGS decoder. Thus the most noticeable problem of using the enhancement layer in prediction is the degraded visual quality caused by drifting because of the mismatch between the reference frame used by the FGS encoder and that by the decoder. To solve this problem, we exploit the principle of cyclical block coding that is used to encode quantized transform coefficients in a cyclical manner in the FGS layer. Encoding block coefficients in a cyclical manner places 'higher-value' bits earlier in the bitstream. The quantized transform coefficients included in the ealry coding cycle of cyclical block coding have higher probability to be correctly received and decoded than the others included in the later cycle of the cyclical block coding. Therefore, we can minimize visual quality degradation caused by bitstream truncation by adjusting weighting factor to control the contribution of the bitstream produced in each coding cycle of cyclical block coding when constructing the enhancement layer reference frame. It is shown by simulations that the improved AR-FGS scheme outperforms the standard AR-FGS by about 1 dB in maximum in the reconstructed visual quality.

Molecular Cloning and Analysis of Nucleotide Sequence of Xylanase Gene (xynk) from Bacillus pumilus TX703 (Bacillus pumilus TX703 유래 Xylanase 유전자(xynK)의 Cloning과 염기서열 분석)

  • 박영서
    • Journal of Life Science
    • /
    • v.12 no.2
    • /
    • pp.188-199
    • /
    • 2002
  • A gene coding for xylanase from thermo-tolerant Bacillus pumilus TX703 was cloned into Escherichia coli DH5 $\alpha$ using pUC19. Among 7,400 transformants, four transformants showed clear zones on the detection agar plates containing oat-spells xylan. One of them which showed highest xylanase activity was selected and its recombinant plasmid, named pXES106, was found to carry 2.24 kb insert DNA fragment. When the nucleotide sequence of the cloned xylanase gene (xynK) was determined, xynK gene was found to consist of 1,227 base-pair open reading frame coding for a polypeptide of 409 amino acids with a deduced molecular weight of 48 kDa. The coding sequence was preceded by a putative ribosome binding site, the transcription initiation signals, and cia-acting catabolite responsive element. The deduced amino acids sequence of xylanase is similar to those of the xylanases from Hordeum vulgare (barley) and Clostridium thermocellum, with 39 and 31% identical residues, respectively. The amino acids sequence of this xylanase was quite different from those of the xylanases from other Bacillus species.

Transform domain Wyner-Ziv Coding based on the frequency-adaptive channel noise modeling (주파수 적응 채널 잡음 모델링에 기반한 변환영역 Wyner-Ziv 부호화 방법)

  • Kim, Byung-Hee;Ko, Bong-Hyuck;Jeon, Byeung-Woo
    • Journal of Broadcast Engineering
    • /
    • v.14 no.2
    • /
    • pp.144-153
    • /
    • 2009
  • Recently, as the necessity of a light-weighted video encoding technique has been rising for applications such as UCC(User Created Contents) or Multiview Video, Distributed Video Coding(DVC) where a decoder, not an encoder, performs the motion estimation/compensation taking most of computational complexity has been vigorously investigated. Wyner-Ziv coding reconstructs an image by eliminating the noise on side information which is decoder-side prediction of original image using channel code. Generally the side information of Wyner-Ziv coding is generated by using frame interpolation between key frames. The channel code such as Turbo code or LDPC code which shows a performance close to the Shannon's limit is employed. The noise model of Wyner-Ziv coding for channel decoding is called Virtual Channel Noise and is generally modeled by Laplacian or Gaussian distribution. In this paper, we propose a Wyner-Ziv coding method based on the frequency-adaptive channel noise modeling in transform domain. The experimental results with various sequences prove that the proposed method makes the channel noise model more accurate compared to the conventional scheme, resulting in improvement of the rate-distortion performance by up to 0.52dB.

Nucleotide Sequence of Cellulolytic Xylanase Gene (bglBC2) from Bacillus circulans (Bacillus circulans 유래 cellulolytic xylanase 유전자(bglBC2)의 염기서열 결정 및 분석)

  • Kim, Ji-Yeon
    • Korean Journal of Microbiology
    • /
    • v.42 no.1
    • /
    • pp.67-72
    • /
    • 2006
  • The nucleotide sequence of the cloned cellulolytic xylanase gene (bglBC2) from B. circulans ATCC21367 was determined. bglBC2 consists of an 1,224 bp open reading frame (ORF) coding for a polypeptide of 407 amino acids with a deduced molecular weight of 45 kDa. The Shine-Dalgarno (SD) sequence (5'-AAAGGAG-3') was found 9 bp upstream of the initiation codon, ATG. A promoter region corresponding closely to the B. subtilis consensus sequence (-35: TTGACA,-10: TATAAT) was detected, the putative -35 and -10 sequences of which were TTTACA and TATACT, respectively. The deduced amino acid sequence of the cellulolytic xylanase showed 97% homology with that of the alkaline $endo-\beta-1,4-glucanase$ from B. circulans KSM-N257, 75% homology with that of the $endo-\beta-1,3-1,4-glucanase$ from B. circulans WL-12, and 45% homology with that of the $endo-\beta-1,4-glucanase$ (cellulase) from Bacillus sp. KSM-330. The bglBC2 sequence was deposited in Gen-Bank under the accession number AY269256.

Efficient Local Decoding Using Bit Stream Map for High Resolution Video (비트 스트림 지도를 이용한 고해상도 영상의 효율적인 지역복호화)

  • Park Sungwon;Won Jongwoo;Lee Sunyoung;Kim Wookjoong;Kim Kyuheon;Jang Euee S
    • Journal of Broadcast Engineering
    • /
    • v.9 no.4 s.25
    • /
    • pp.391-401
    • /
    • 2004
  • In this paper, we introduce a novel coding method to efficiently enable spatial random access for high resolution video. In terms of resolution and display size, standard display devices (such as cathode-ray tubes. monitors. PDAs, and LCDs) do not sufficiently support high resolution video such as digital cinema and panoramic video. Currently, users have no choice but to view video at lower resolution as a result of down-sampling, or only a partial region of the video due to display size limitations. Our proposed method. which we call the B-map, represents the set of starting locations of the coded segments in a picture frame. This information, or B-map, is first sent to the decoder prior to the coded data stream of the frame and is then used for fast local decoding. To test our method, we compare our B-map with JPEG tiling and the JPEG Resynchronization marker. Experimental results show that the proposed coding method requires less overhead than existing methods during the same decoding time. The results show promise for future panoramic or digital cinema applications.

Cloning and Sequence Analysis of the trpB, trpA and 3' trpC(F) Gens of Vibrio metschnikovii Strain RH530 (Vibrio metschnikovii 균주 RH530의 trpB, trpA 그리고 3' trpC(F) 유전자의 클로닝 및 염기서열 결정)

  • Kwon, Yong-Tae;Kim, Jin-Oh;Yoo, Young-Dong;Rho, Hyune-Mo
    • Korean Journal of Microbiology
    • /
    • v.32 no.2
    • /
    • pp.120-125
    • /
    • 1994
  • The genes, trpB, trpA and 3’ trpC(F) of Vibrio metschnikovii strain RH530 were cloned and sequenced. The trpB and trpA genes had open reading frames of 1,173 bp and 804 bp encoding 391 and 268 amino acids, respectively. The trpB and trpA genes had conventional ribosome-binding sequences and overlapped with each other by one nucleotide, suggesting that these two genes are translationally coupled. 115 nucleotide upstream the trpB start codon, tjere was an incomplete open reading frame of the 3’-end of the trpC(F). The amino acid sequences of trpB, trpA and trpC(F) of V. metschnikovii RH530 had identities of 64.2%, 82.4% and 73.7% respectively, for those of V. parahaemolyticus; 58.7%, 72.3% and 54.9%, respectively, for Salmonella typhimurium; and 42.6%. 54.1% and 12.5%, respectively, for brevibacterium lactofermentum. The genetic organization of these genes, especially in the noncoding region between trpC(F) and trpB, was distinct from that of Enterobacteriaceae.

  • PDF

Genomic Analyses of Toll-like Receptor 4 and 7 Exons of Bos indicus from Temperate Sub-himalayan Region of India

  • Malik, Y.P.S.;Chakravarti, S.;Sharma, K.;Vaid, N.;Rajak, K.K.;Balamurugan, V.;Biswas, S.K.;Mondal, B.;Kataria, R.S.;Singh, R.K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.24 no.7
    • /
    • pp.1019-1025
    • /
    • 2011
  • Toll-like receptors (TLRs) play an important role in the recognition of invading pathogens and the modulation of innate immune responses in mammals. The TLR4 and TLR7 are well known to recognize the bacterial lipopolysaccharide (LPS) and single stranded (ssRNA) ligands, respectively and play important role in host defense against Gram-negative bacteria and ssRNA viruses. In the present study, coding exon fragments of these two TLRs were identified, cloned, sequenced and analyzed in terms of insertion-deletion polymorphism, within bovine TLRs 4 and 7, thereby facilitating future TLR signaling and association studies relevant to bovine innate immunity. Comparative sequence analysis of TLR 4 exons revealed that this gene is more variable, particularly the coding frame (E3P1), while other parts showed percent identity of 95.7% to 100% at nucleotide and amino acid level, respectivley with other Bos indicus and Bos taurus breeds from different parts of the world. In comparison to TLR4, sequence analysis of TLR7 showed more conservation among different B. indicus and B. taurus breeds, except single point mutation at 324 nucleotide position (AAA to AAM) altering a single amino acid at 108 position (K to X). Percent identity of TLR7 sequences (all 3 exons) was between 99.2% to 100% at nucleotide and amino acid level, when compared with available sequence database of B. indicus and B. taurus. Simple Modular Architecture Research Tool (SMART) analysis showed variations in the exon fragments located in the Leucine Rich Repeat (LRR) region, which is responsible for binding with the microbial associated molecular patterns and further, downstream signaling to initiate anti-microbial response. Considering importance of TLR polymorphism in terms of innate immunity, further research is warranted.