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Achieving the Gaussian ratedistortion function by prediction
 IEEE Trans. Inf. Theory
, 2008
"... Abstract — The “waterfilling ” solution for the quadratic ratedistortion function of a stationary Gaussian source is given in terms of its power spectrum. This formula naturally lends itself to a frequency domain “testchannel ” realization. We provide an alternative timedomain realization for the ..."
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Cited by 38 (12 self)
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Abstract — The “waterfilling ” solution for the quadratic ratedistortion function of a stationary Gaussian source is given in terms of its power spectrum. This formula naturally lends itself to a frequency domain “testchannel ” realization. We provide an alternative timedomain realization for the ratedistortion function, based on linear prediction. The predictive testchannel has some interesting implications, including the optimality at all distortion levels of pre/post filtered vectorquantized differential pulse code modulation (DPCM), and a duality relationship with decisionfeedback equalization (DFE) for intersymbol interference (ISI) channels. I.
Inferior temporal neurons show greater sensitivity to nonaccidental than to metric shape differences
 Journal of Cognitive Neuroscience
, 2001
"... & It has long been known that macaque inferior temporal (IT) neurons tend to fire more strongly to some shapes than to others, and that different IT neurons can show markedly different shape preferences. Beyond the discovery that these preferences can be elicited by features of moderate complexi ..."
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Cited by 29 (6 self)
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& It has long been known that macaque inferior temporal (IT) neurons tend to fire more strongly to some shapes than to others, and that different IT neurons can show markedly different shape preferences. Beyond the discovery that these preferences can be elicited by features of moderate complexity, no general principle of (nonface) object recognition had emerged by which this enormous variation in selectivity could be understood. Psychophysical, as well as computational work, suggests that one such principle is the difference between viewpointinvariant, nonaccidental (NAP) and viewdependent, metric shape properties (MPs). We measured the responses of single IT neurons to objects differing in either a NAP (namely, a change in a geon) or an MP of a single part, shown at two orientations in depth. The cells were more sensitive to changes in NAPs than in MPs, even though the image variation (as assessed by waveletlike measures) produced by the former were smaller than the latter. The magnitude of the response modulation from the rotation itself was, on average, similar to that produced by the NAP differences, although the image changes from the rotation were much greater than that produced by NAP differences. Multidimensional scaling of the neural responses indicated a NAP/MP dimension, independent of an orientation dimension. The present results thus demonstrate that a significant portion of the neural code of IT cells represents differences in NAPs rather than MPs. This code may enable immediate recognition of novel objects at new views. &
Pattern Matching in Compressed Text and Images
, 2001
"... Normally compressed data needs to be decompressed before it is processed, but if the compression has been done in the fight way, it is often possible to search the data without having to decompress it, or at least only partially decompress it. The problem can be divided into lossless and lossy c ..."
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Cited by 13 (11 self)
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Normally compressed data needs to be decompressed before it is processed, but if the compression has been done in the fight way, it is often possible to search the data without having to decompress it, or at least only partially decompress it. The problem can be divided into lossless and lossy compression methods, and then in each of these cases the pattern matching can be either exact or inexact. Much work has been reported in the literature on techniques for all of these cases, including algorithms that are suitable for pattern matching for various compression methods, and compression methods designed specifically for pattern matching. This work is surveyed in this paper. The paper also exposes the important relationship between pattern matching and compression, and proposes some performance measures for compressed pattern matching algorithms. Ideas and directions for future work are also described.
About Priority Encoding Transmission Stéphane Boucheron, Member, IEEE, and
"... Abstract—Recently, Albanese et al. introduced priority encoding transmission (PET) for sending hierarchically organized messages over lossy packetbased computer networks [1]. In a PET system, each symbol in the message is assigned a priority which determines the minimal number of codeword symbols ..."
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Abstract—Recently, Albanese et al. introduced priority encoding transmission (PET) for sending hierarchically organized messages over lossy packetbased computer networks [1]. In a PET system, each symbol in the message is assigned a priority which determines the minimal number of codeword symbols that is required to recover that symbol. This note revisits the PET approach using tools from network information theory. We first outline that priority encoding transmission is intimately related with the broadcast erasure channel with degraded message set. Using the information spectrum approach, we provide an informational characterization of the capacity region of general broadcast channels with degraded message set. We show that the PET inequality has an informationtheoretical counterpart: The inequality defining the capacity region of the broadcast erasure channel with degraded message sets. Hence the PET approach which consists in timesharing and interleaving classical erasureresilient codes achieves the capacity region of this channel. Moreover, we show that the PET approach may achieve the sphere packing exponents. Finally, we observe that on some simple nonstationary broadcast channels, timesharing may be outperformed. The impact of memory on the optimality of the PET approach remains elusive. Index Terms—Broadcast channels, coding exponents, erasureresilient codes, information spectrum, priority encoding transmission. I.
Achieving the Gaussian RateDistortion Function by Prediction
"... Abstract — The “waterfilling ” solution for the quadratic ratedistortion function of a stationary Gaussian source is given in terms of its power spectrum. This formula naturally lends itself to a frequency domain “testchannel ” realization. We provide an alternative timedomain realization for the ..."
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Abstract — The “waterfilling ” solution for the quadratic ratedistortion function of a stationary Gaussian source is given in terms of its power spectrum. This formula naturally lends itself to a frequency domain “testchannel ” realization. We provide an alternative timedomain realization for the ratedistortion function, based on linear prediction. This solution has some interesting implications, including the optimality at all distortion levels of vectorquantized differential pulse code modulation (DPCM), and a duality relationship with decisionfeedback equalization (DFE) for intersymbol interference (ISI) channels. I. INTRODUCTION: RATEDISTORTION AND PREDICTION The ratedistortion function (RDF) of a stationary source with memory is given by a time domain formula, that is, as a limit of normalized mutual informations associated
Optimal Parametric BackwardAdaptive Lossy Compression ∗
, 2005
"... We present a new generic mechanism for “online ” construction of a vector quantizer codebook, based on blockwise backwardadaptive parametric encoding. The workings of the proposed scheme is explained by the principle of “natural type selection”: In the limit of large vector dimension, the type of ..."
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We present a new generic mechanism for “online ” construction of a vector quantizer codebook, based on blockwise backwardadaptive parametric encoding. The workings of the proposed scheme is explained by the principle of “natural type selection”: In the limit of large vector dimension, the type of the first distortionmatching codeword within a random codebook coincides with an iteration of the BlahutArimoto algorithm for computation of the ratedistortion function. We extend this observation to parametric codebooks, and demonstrate that the parameter sequence converges to an optimum solution within the reproduction class. In comparison to other methods, adaptation is simple due to the parametric model, yet it is optimal even in the low coding rate regime. Keywords: parametric encoding, natural type selection, ArimotoBlahut algorithm, vector quantization, alternating minimization, universal coding, approximate string matching.
Achieving the Gaussian RateDistortion Function by Prediction
"... Abstract — The “waterfilling ” solution for the quadratic ratedistortion function of a stationary Gaussian source is given in terms of its power spectrum. This formula naturally lends itself to a frequency domain “testchannel ” realization. We provide an alternative timedomain realization for the ..."
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Abstract — The “waterfilling ” solution for the quadratic ratedistortion function of a stationary Gaussian source is given in terms of its power spectrum. This formula naturally lends itself to a frequency domain “testchannel ” realization. We provide an alternative timedomain realization for the ratedistortion function, based on linear prediction. This solution has some interesting implications, including the optimality at all distortion levels of pre/post filtered vectorquantized differential pulse code modulation (DPCM), and a duality relationship with decisionfeedback equalization (DFE) for intersymbol interference (ISI) channels. I.
University of Southern Queensland Faculty of Engineering and Surveying Fractal Video Compression
, 2005
"... With the rapid increase in the use of computers and internet, the demand for higher transmission and better storage is increasing as well. One way to solve this problem is by using compression, in which a small amount of data can represent the much larger amount of original data. This dissertation d ..."
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With the rapid increase in the use of computers and internet, the demand for higher transmission and better storage is increasing as well. One way to solve this problem is by using compression, in which a small amount of data can represent the much larger amount of original data. This dissertation describes the different techniques for data (imagevideo) compression in general and, in particular, the new compression technique called Fractal Image Compression. Fractal image compression is based on selfsimilarity, where one part of an image is similar to the other part of the same image. The most significant aspect of this project is the development of color images using fractalbased color image compression, since little work has been done previously in this area. The results obtained show that the fractalbased compression for the color images works as well as for the grayscale images. Nevertheless, the encoding of the color images takes more time than the grayscale images. i
Universal Successive Refinement Of Celp Speech Coders
"... Many speech coding standards are based upon codeexcited linear prediction (CELP), and it is desirable to develop layered coding methods that are compatible with this installed base of coders. We propose a layered speech coding structure that is universally compatible with all CELPbased coders. Thi ..."
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Many speech coding standards are based upon codeexcited linear prediction (CELP), and it is desirable to develop layered coding methods that are compatible with this installed base of coders. We propose a layered speech coding structure that is universally compatible with all CELPbased coders. This structure encodes the reconstruction error signal from layer 1 using a lowdelay, adaptive tree coder based upon the mean squared error (MSE) criterion. We note that rate distortion optimal successive refinement is achievable using two different distortion criteria and we derive expressions for the rate distortion function under autoregressive Gaussian assumptions on the source and the two different distortion measures. We demonstrate the universality of the approach by developing twolayer coders for a 3.65 kbps CELP coder, G.723.1, and G.729. We show that our layering method is favorably competitive with the MPEG4 layering method at 8.7 kbps for both clean and noisy speech. Using tree coding and the MSE criterion in layer 2 improves speech naturalness when coding noisy speech.