Summary form only given. We designed a family of integer-to-integer (i2i) approximations to the Cartesian-to-polar transformation and analyzed its behavior for high-rate transform coding. Denoting (ordinary, continuou...
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Summary form only given. We designed a family of integer-to-integer (i2i) approximations to the Cartesian-to-polar transformation and analyzed its behavior for high-rate transform coding. Denoting (ordinary, continuous) polar coordinates by (r, 0), our precise high-rate analysis relates the performance to the differential entropies of r 2 and 0, which are often easy to evaluate. One may thus predict when there is an improvement over linear transform coding. The analysis matches our simulations for coding of Gaussian scale mixtures and other polar-separable sources. The advantage over the best linear transform coder can be large. Our hope is to extend the polar-coordinate results to a general theory for nonlinear transform coding based on i2i implementations of arbitrary nonlinear transformations
In bit-interleaved coded modulation (BICM) the coding and modulation schemes were jointly optimized for the sake of attaining the best possible performance when communicating over fading wireless communication channel...
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In bit-interleaved coded modulation (BICM) the coding and modulation schemes were jointly optimized for the sake of attaining the best possible performance when communicating over fading wireless communication channels. The iterative decoding scheme of BICM (BICM-ID) invoking an appropriate bit-to-symbol mapping strategy enhances its achievable performance in both AWGN and Rayleigh channels. BICM-ID may be conveniently combined with Luby transform (LT) codes, which were designed for handling packetized wireless Internet data traffic in erasure channels without retransmitting the corrupted packets. By jointly designing a serially concatenated LT-BICM-ID code, an infinitesimally low bit error rate (BER) is achieved for signal to noise ratios (SNR) in excess of 7.5 dB over wireless Internet type erasure channels contaminated by AWGN
The theory and implementation of the k-t approach (k-t BLAST and k-t SENSE) are reviewed in the context of transform coding. The k-t approach exploits the information redundancy in typical time series of magnetic reso...
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The theory and implementation of the k-t approach (k-t BLAST and k-t SENSE) are reviewed in the context of transform coding. The k-t approach exploits the information redundancy in typical time series of magnetic resonance images that depict anatomy and/or functional parameters. By utilizing this redundancy, it opens up the opportunity for significant acceleration, which in turn allows for scan time reduction, improvements in spatial or temporal resolution, or extended volume coverage for a given acquisition time
In using partial transform for the coding of hyperspectral image, it must consider spectral decorrelation between image components, issues that a combined adaptive classification and partial transform algorithm for hy...
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In using partial transform for the coding of hyperspectral image, it must consider spectral decorrelation between image components, issues that a combined adaptive classification and partial transform algorithm for hyperspectral image compression is presented in this paper. Our method uses a linear prediction based on adaptive classification to decorrelate the spectrum redundancy and a 2D integer reversible DCT-based scheme as spatial compression engine. The classification includes band ordering, band regrouping and reference frame selection. Experimental results on AVIRIS data indicate that the proposed approach is a novel low complexity lossy hyperspectral image compression scheme and exhibits performance better than other comparative methods in quality and fidelity. It can be used for hyperspectral image compression in the embedded processor of the platform on satellite or aircraft
This paper proposes a hybrid transform coding technique, where the intraframes of video sequence are coded by discrete wavelet transform and the interframes are coded with discrete cosine transform technique. It also ...
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This paper proposes a hybrid transform coding technique, where the intraframes of video sequence are coded by discrete wavelet transform and the interframes are coded with discrete cosine transform technique. It also proposes the selection of sequence of frames predicted from the reference intraframes. This proposal consistently minimizes the prediction error for the predicted frame for further processing. The experimental results show that the proposed hybrid transformation coding technique outperforms over conventional transformation coding technique in terms of encoding time and prediction errors.
This paper proposed a novel extension of bus-invert coding to handle 4-level pulse amplitude modulated (PAM-4) signals. A generalized mathematical model for energy consumption and energy dissipation for PAM-4 signals ...
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This paper proposed a novel extension of bus-invert coding to handle 4-level pulse amplitude modulated (PAM-4) signals. A generalized mathematical model for energy consumption and energy dissipation for PAM-4 signals is presented and a family of coding schemes are developed that can reduce the average power consumption and dissipation by up to 54% compared to un-coded PAM-4 buses. This technique is attractive for high-speed data transmission systems that employ PAM-4 signals on general high capacitance buses such as global wires, off-chip buses, I/O and backplanes
transform coding is a essential tool for picture coding applications, and coding schemes that can achieve high energy compaction are essential. In terms of energy compaction, Karhunen-Loeve transform (KLT) is known to...
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ISBN:
(纸本)9781424456536
transform coding is a essential tool for picture coding applications, and coding schemes that can achieve high energy compaction are essential. In terms of energy compaction, Karhunen-Loeve transform (KLT) is known to be optimal. The energy compaction provided by KLT depends on the statistical property of the input signal and the dimensionality of KLT. However, the quantitative effect of KLT dimensionality on energy compaction has not been clarified. This paper establishes a mathematical model of the relationship among the dimensionality of KLT and the energy compaction of the transform coefficients, using mathematical tools in quantum information theory.
Increasingly, we can obtain more than one compressed copy of the same video content with different levels of visual quality over the Internet. As the original source video is not always available, how to choose or der...
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ISBN:
(纸本)9781424456536
Increasingly, we can obtain more than one compressed copy of the same video content with different levels of visual quality over the Internet. As the original source video is not always available, how to choose or derive a video of the best quality from these copies becomes a challenging and interesting problem. In this paper, we address this new research problem by blindly enhancing the quality of the video reconstructed from multiple compressed copies of the same video content. The aim is to reconstruct a video that achieves better quality than any of the available copies. Specifically, we propose to reconstruct each coefficient of the video in the transform domain by using a narrow quantization constraint set derived from the multiple compressed copies together with the Cauchy distribution model for each AC transform coefficient to minimize the distortion. Analytical and experimental results show the effectiveness of the proposed method.
Local features are widely used for content-based image retrieval and object recognition. We present an efficient method for encoding digital images suitable for local feature extraction. First, we find the patches in ...
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ISBN:
(纸本)9781424423538
Local features are widely used for content-based image retrieval and object recognition. We present an efficient method for encoding digital images suitable for local feature extraction. First, we find the patches in the image corresponding to the detected features. Then, we extract these patches at their characteristic scale and orientation and encode them for efficient transmission. A Discrete Cosine transform (DCT) with adaptive block size is used for patch compression. We compare this method to directly compressing feature descriptors using transform coding. Experimental results show the superior performance of our technique. Image patches can be compressed to rates around 55 bits/patch (18x compression relative to uncompressed SIFT feature descriptors) and still achieve good image matching performance.
Most current steganalysis schemes are based on the Cachin's statistical undetectability. However, the lack of the statistical model for the natural images the performance of the current steganalyzers. In this pape...
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ISBN:
(纸本)9781424444564
Most current steganalysis schemes are based on the Cachin's statistical undetectability. However, the lack of the statistical model for the natural images the performance of the current steganalyzers. In this paper, we propose a novel steganalyzer for JPEG images based on manifold learning, which overcomes the statistical steganalyzer's deficiencies. The feature extraction in this steganalyzer is completed by the nonlinear dimensionality reduction method (ISOMAP), which will greatly reduce the dimensionality of the feature space without influencing the performance of our steganalyzer. Experimental results show the effectiveness of this method and also demonstrate the promise of the proposed scheme used both as a specific and a blind steganalyzer.
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