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predictive vector quantization of wideband LSF using narrowband LSF for bandwidth scalable coders

SPEECH COMMUNICATION 2007年第6期49卷 490-500页

作者： Ehara, Hiroyuki Morii, Toshiyuki Yoshida, Koji Matsushita Elect Ind Co Ltd Panasonic Next Generat Mobile Commun Dev Ctr Yokosuka Kanagawa 2390847 Japan

For implementing a bandwidth-scalable coder, a wideband line spectral frequency (LSF) quantizer was developed. It works in combination with a narrowband LSF quantizer. A new predictive vector quantization was introduced to the wideband LSF quantizer. The predictive vector quantizer is based on the use of several predictive contributions, which include first-order auto regressive (AR) prediction and vector quantization (VQ) codebook mapping. One feature of the new predictive vector quantizer is exploitation of the correlation between wideband and narrowband LSFs quantized in the previous frame for estimating wideband LSF in the current frame. A 16-bit switched predictive three-stage vector quantizer was used to encode estimation residues. Results showed that introduction of the predictor brought about a performance improvement of 0.3 dB in spectral distortion. This paper describes procedures of designing the predictor and the three-stage codebook, as well as simulation results. (C) 2007 Elsevier B.V. All rights reserved.

关键词： predictive vector quantization LSF LSP bandwidth scalability codebook mapping

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predictive vector quantization using neural networks 2

Predictive vector quantization using neural networks

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Conference on Applications of Artificial Neural Networks in Image Processing II

作者： Hashemi, MR Yeap, TH Panchanathan, S UNIV OTTAWA DEPT ELECT ENGNVISUAL COMP & COMMUN LABOTTAWAON K1N 6N5CANADA

ISBN: (纸本)0819424412

In this paper we propose a new scalable predictive vector quantization (PVQ) technique for image and video compression, This technique has been implemented using neural networks. A Kohonen self organized feature may, is used to implement the vector quantizer, while a multilayer perceptron implements the predictor. Simulation results demonstrate that the proposed technique provides a 5-10% improvement in coding performance over the existing neural networks based PVQ techniques.

关键词： predictive vector quantization neural networks image compression multimedia

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Channel optimized predictive vector quantization

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IEEE TRANSACTIONS ON SPEECH AND AUDIO PROCESSING 2000年第4期8卷 370-384页

作者： Lindén, J Chalmers Univ Technol Dept Signals & Syst SE-41296 Gothenburg Sweden

The objective of this work is to investigate how channel optimization techniques ran be applied to predictive vector quantizers. In particular, an efficient encoder search procedure and two design methods are derived. The design methods proposed here, one sample iterative and one block iterative, simultaneously optimize the predictor and the codebook, Extensive simulations show the advantage of this quantization method compared to other memory based quantization schemes as well as memoryless VQ, We also demonstrate that the design methods can be used to obtain index assignments that are advantageous to what is obtained by post process index assignment algorithms.

关键词： channel optimized vector quantization index assignment noisy channels predictive vector quantization spectrum coding vector quantization

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ADAPTIVE ENTROPY-CODED PRUNED TREE-STRUCTURED predictive vector quantization OF IMAGES

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IEEE TRANSACTIONS ON COMMUNICATIONS 1993年第1期41卷 171-185页

作者： KIM, YH MODESTINO, JW Department of Electrical Computer and Systems Engineering Rensselaer Polytechnic Institute Troy NY USA

In recent work, we described an adaptive entropycoded predictive vector quantization (PVQ) scheme for images which was shown to be capable of excellent rate-distortion performance and to be surprisingly robust when applied to images outside the training set used in its design. This scheme made use of several entropy-constrained vector quantizers (ECVQ's), each with a corresponding Huffman encoder/decoder pair, embedded in a vector predictive feedback loop. The particular entropy-coded ECVQ in effect for any input image block depended upon the instantaneous occupancy state of a buffer used to interface the resulting variable-length codewords to a fixed-rate transmission or storage channel. This entropy-coded PVQ scheme is a vector extension of previous work on adaptive entropy-coded predictive scalar quantization (PSQ);in particular, 2-D DPCM. The embedded ECVQ in this adaptive entropy-coded PVQ scheme made use of a modification of a recently introduced design algorithm, based upon clustering, which resulted in unstructured codebooks. Unfortunately, the computational complexity associated with this unstructured embedded ECVQ can be substantial. In this paper we describe much simpler versions of this adaptive entropy-coded PVQ scheme where the embedded ECVQ is replaced by a pruned tree-structured VQ (PTSVQ). The resulting encoding scheme is shown to result in drastically reduced complexity at only a small cost in performance. We demonstrate coding results on selected real-world images.

关键词： Entropy coding predictive vector quantization Coding systems vector quantization Self tuning

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predictive vector quantization with intrablock prediction support region

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IEEE TRANSACTIONS ON IMAGE PROCESSING 1999年第2期8卷 293-295页

作者： Klautau, ABD Univ Calif San Diego Dept Elect & Comp Engn La Jolla CA 92093 USA

A predictive vector quantization (PVQ) structure is proposed, where the encoder uses a predictor based on an intrablock support region, followed by a modified vector quantizer stage. Simulation results show that a mod... 详细信息

关键词： image coding predictive vector quantization vector quantization

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Channel Prediction and predictive vector quantization Aided Channel Impulse Response Feedback for SDMA Downlink Preprocessing

Channel Prediction and Predictive Vector Quantization Aided ...

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68th IEEE Vehicular Technology Conference

作者： Yang, Du Liu, Wei Yang, Lie-Liang Hanzo, Lajos Univ Southampton Sch ECS Southampton SO17 1BJ Hants England

ISBN: (纸本)9781424417223;9781424417216

Invoking SDMA in the Down-Link (DL) has the potential of increasing the achievable throughput with the aid of linear transmit preprocessing, provided that the Channel Impulse Responses (CIRs) of all users and all antenna elements are known at the DL transmitter. However, in a Frequency Division Duplex (FDD) system, since these CIRs have to be transmitted by the Mobile Terminals (MTs) to the Base Station (BS), they are naturally out-dated. Hence, we proposed a periodical CIR update scheme employing a channel predictor at the DL transmitter for predicting the CIR taps for each future symbol transmission instant and hence to mitigate the performance degradation imposed by the associated signalling delays. Moreover, a predictive vector Quantizer (PVQ) is used at the MTs for compressing the CIRs before their uplink transmission. Compared to a conventional vector Quantizer (VQ), PVQ has significantly reduced the CIR feedback bit rate. Hence, with the aid of the same feedback bit rate, the new PVQ scheme can provide more accurate CIR information or support a channel having a higher Doppler frequency.

关键词： SDMA channel prediction predictive vector quantization feedback out-dated

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Rate-constrained modular predictive residual vector quantization of digital images

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IEEE SIGNAL PROCESSING LETTERS 1999年第6期6卷 135-137页

作者： Rizvi, SA Wang, LC Nasrabadi, NM CUNY Coll Staten Isl Dept Engn Sci & Phys Staten Isl NY 10314 USA SONY Semicond Co Amer San Jose CA 95134 USA USA Res Lab Adelphi MD 20903 USA

In this letter, a novel modular coding paradigm is investigated using residual vector quantization (RVQ) with memory that incorporates a modular neural network vector predictor in the feedback loop, A modular neural network predictor consists of several expert networks that are optimized for predicting a particular class of data. The predictor also consists of an integrating unit that mixes the outputs of the expert networks to form the final output of the prediction system. The vector quantizer also has a modular structure. The proposed modular predictive RVQ (modular PRVQ) is designed by imposing a constraint on the output rate of the system. Experimental results show that the modular PRVQ outperforms simple PRVQ by as much as 1 dB at low bit rates. Furthermore, for the same peak signal-to-noise ratio (PSNR), the modular PRVQ reduces the bit rate by more than a half when compared to the JPEG algorithm.

关键词： image coding modular neural network predictive vector quantization

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predictive vector Quantized Variational AutoEncoder for Spectral Envelope quantization

Predictive Vector Quantized Variational AutoEncoder for Spec...

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19th International Conference on Electronics, Information, and Communication (ICEIC)

作者： Srikotr, Tanasan Mano, Kazunori Shibaura Inst Technol Grad Sch Engn & Sci Div Funct Control Syst Tokyo Japan

ISBN: (纸本)9781728162898

The predictive vector Quantized Variational AutoEncoder is proposed to improve the reconstruction error of the conventional VQ-VAE. The proposed model can predict the current data from the previous data. The performance of the quantized spectral envelope parameters of the high-quality 48 kHz WORLD vocoder is evaluated. The results indicate that the predictive vector Quantized Variational AutoEncoder has a lower distortion with four target bitrates in term of log-spectral distortion, compared with the conventional VQ-VAE.

关键词： predictive vector quantization spectral envelope vector quantized variational autoencoder WORLD vocoder

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The asymptotic closed-loop approach to predictive vector quantizer design with application in video coding

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2001年第1期10卷 15-23页

作者： Khalil, H Rose, K Regunathan, SL Univ Calif Santa Barbara Dept Elect & Comp Engn Santa Barbara CA 93106 USA

The basic vector quantization (VQ) technique employed in video coding belongs to the category of predictive vector quantization (PVQ), as it involves quantization of the (motion compensated) frame prediction error. It is well known that the design of PVQ suffers from fundamental difficulties, due to the prediction loop, which have an impact on the convergence and the stability of the design procedure. In this paper we propose an approach to PVQ design that enjoys the stability of open-loop design while it ensures ultimate optimization of the closed-loop system. The method is derived for general predictive quantization, and we demonstrate it on video compression at low bit rates, where it provides substantial improvement over standard open and closed loop design techniques. Further, the approach outperforms standard DCT-based video coding.

关键词： predictive vector quantization video coding

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Perceptual coding of narrow-band audio signals at low rates

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IEEE TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING 2006年第2期14卷 609-622页

作者： Najaf-Zadeh, H Kabal, P Adv Audio Syst Commun Res Ctr Ottawa ON K2H 8S2 Canada McGill Univ Montreal PQ H3A 2A7 Canada

This paper describes a coding paradigm using coding tools based on the characteristics of the human hearing system so as to accommodate a wide range of narrow-band audio inputs without annoying artifacts at low rates (down to 8 kb/s). The narrow-band perceptual audio coder (NPAC) employs a variety of algorithms to account for the perceptually irrelevant parts of the input signal in addition to statistical redundancies. The new algorithms used in the NPAC coder include a perceptual error measure in training the codebooks and selecting the best codewords which takes into account the audible parts of the quantization noise, a perception-based bit-allocation algorithm and a new predictive scheme to vector quantize the scale factors. The NPAC coder delivers acceptable quality without annoying artifacts for most narrow-band audio signals at around 1 bit/sample. Informal subjective tests have shown that the NPAC coder outperforms a commercial low-rate music coder operating at 8 kb/s.

关键词： adaptive bit allocation masking model modified discrete cosine transform filter bank narrow-band audio coding perceptual audio coding perceptual distortion perceptual vector quantization predictive vector quantization

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