The quad-tree structured motion-compensation technique effectively utilizes the motion content of a frame as opposed to the fixed size block motion compensation technique. The authors propose a novel quad-tree structu...
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The quad-tree structured motion-compensation technique effectively utilizes the motion content of a frame as opposed to the fixed size block motion compensation technique. The authors propose a novel quad-tree structured region-wise motion compensation technique that divides a frame into equilateral triangle blocks using the quad-tree structure. Arbitrary partition shapes are achieved by allowing 4-to-1, 3-to-1 and 2-1 merge/combine of sibling blocks having the same motion vector. We propose an optimal code scheme and a temporal predictive coding for the quad-tree. Simulation results show that our techniques reduce the bit rate by 40% as compared to other methods.
Presented is an embedded coding strategy for wideband signals using the multimode transform predictive coding (MTPC) framework. The design uses many of the inherently layered features of the original non-embedded MTPC...
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Presented is an embedded coding strategy for wideband signals using the multimode transform predictive coding (MTPC) framework. The design uses many of the inherently layered features of the original non-embedded MTPC including iterative bit assignments and frequency domain coding. The design also uses the mode decision of the MTPC to adapt the layering strategy to the type input signal. The result is a high quality embedded wideband coder with multiple enhancement layers and little compromise in performance when compared to non-embedded MTPC designs.
We propose a variable dimensional algebraic codebook structure in order to quantize the prototype waveforms efficiently. The proposed algorithm adjusts the interval of candidate pulse positions in a codevector accordi...
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We propose a variable dimensional algebraic codebook structure in order to quantize the prototype waveforms efficiently. The proposed algorithm adjusts the interval of candidate pulse positions in a codevector according to the pitch period. The analysis-by-synthesis search procedure is computationally efficient due to the characteristics of the algebraic codebook structure. We also develop a method to perceptually improve the basis pulse of codevectors, which enhances the reconstructed speech quality with little increase in computational complexity. The improved prototype waveform interpolation coder adopting the proposed methods achieves a high quality of speech at 4 kbps.
In sinusoidal speech coding, the LP-spectral envelope is limited in its spectral accuracy if the order of the LP-model is not high enough. Thus the quantization of the residual spectrum of the low order LP-model may b...
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In sinusoidal speech coding, the LP-spectral envelope is limited in its spectral accuracy if the order of the LP-model is not high enough. Thus the quantization of the residual spectrum of the low order LP-model may be desirable for good quality speech reconstruction. From the investigation of the magnitude of the LP-residual spectrum, it is found that the predictive coding scheme is useful for removing coding redundancy considerably. The problem of having a variable number of harmonics due to pitch changes can be alleviated by a length warping technique. Subsequently, the residual spectrum of the predictive coding is represented by mel-scale binary vector quantizer (MBVQ), which quantizes the residual spectrum by splitting harmonic bands of variable dimension into a fixed dimension, based on mel scale, and representing each element of the code vector as a binary value. The optimal code vector for the MBVQ can be derived by minimizing an error measure, defined as the weighted square-sum of the difference between original and synthesized spectral envelopes. From the performance evaluation, it is shown that the predictive-coded MBVQ with low order LP can obtain the effect of considerably high order LP-model. Additionally, the proposed method can be implemented with very low computational complexity in time and space.
Studies parallel processing algorithms of linear prediction of speech parameters. The autoregressive speech vector series with stable covariance, can be gained after a classification of adjacent samples of source spee...
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Studies parallel processing algorithms of linear prediction of speech parameters. The autoregressive speech vector series with stable covariance, can be gained after a classification of adjacent samples of source speech series. A strategy of vector predictive coding with highly parallel processing ability can be achieved with the application of the principle of orthogonal projection in Hilbert space. Finally it is confirmed that the algorithms are effective by computer simulation.
Summary form only given. We propose a lossless algorithm of delta compression (a variant of predictive coding) that attempts to predict the next point from previous points using higher-order polynomial extrapolation. ...
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Summary form only given. We propose a lossless algorithm of delta compression (a variant of predictive coding) that attempts to predict the next point from previous points using higher-order polynomial extrapolation. In contrast to traditional predictive coding our method takes into account varying (non-equidistant) domain (typically, time) steps. To save space and guarantee lossless compression, the actual and predicted values are converted to 64-bit integers. The residual (difference between actual and predicted values) is computed as difference of integers. The unnecessary bits of the residual are truncated, e.g., 1111110101 is replaced by 10101. The length of the bit sequence (5/sub 10/=(000101)/sub 2/) is prepended.
We propose a new approach to context-based predictive coding of video, where the interframe or intraframe coding mode is adaptively selected on a pixel basis. We perform the coding mode selection using only the previo...
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ISBN:
(纸本)0780362977
We propose a new approach to context-based predictive coding of video, where the interframe or intraframe coding mode is adaptively selected on a pixel basis. We perform the coding mode selection using only the previously reconstructed samples which are also available at the decoder, so that any overhead information on the coding mode selection does not need to be transmitted to the decoder. The proposed coder also provides the lossless concatenated coding property when applied to multigeneration of video sequences since the same coding mode information is available at the second time encoding. The proposed coding mode selection enables the coder to easily incorporate error modeling and context modeling by performing the intraframe coding with one of the existing image coders such as the JPEG-LS standard. Experiments show that the proposed approach in conjunction with the JPEG-LS standard provides significant improvements in compression efficiency.
Image coding is discussed in two phases;one is transformation of image signals using a coding model, and the other is entropy coding which assigns a code to a transformed sequence. A well-known example of the latter i...
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Image coding is discussed in two phases;one is transformation of image signals using a coding model, and the other is entropy coding which assigns a code to a transformed sequence. A well-known example of the latter is arithmetic coding. Because arithmetic coding makes dynamic adaptation rather easy, it is used in efficient entropy coding of signals, such as image signals, whose statistical characteristics vary locally. Though adaptation is an effective measure to achieve efficient coding, it requires longer processing time and larger hardware size. The authors have proposed multialphabet arithmetic coding with a 1/2(n) rate approximation, whose algorithm is simple. This arithmetic coding can be performed with an extremely small amount of multiplication, and it can be extended to adaptation simply by recalculation of cumulative approximate probability. In this article, we will propose a method that optimizes update timing in adaptation, and show that we obtained satisfactory results in efficiency and coding speed. (C) 2000 Scripta Technica.
We propose a new approach to document image layout extraction using rapid feature analysis, preclassification and predictive coding. First, a set of layout features is used to render the image profile information, The...
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ISBN:
(纸本)0818680555
We propose a new approach to document image layout extraction using rapid feature analysis, preclassification and predictive coding. First, a set of layout features is used to render the image profile information, The knowledge base is utilized to rule these early regions into layout labels. The regions found are given a classification tag and a degree of membership into background, text, picture and linedrawing classes. A predictive coding method is used with the preclassification information to rise the confidence of each label, and To integrate the regional domain and the labels into a uniform class without any shape assumption. We have tested our technique using three different databases that comprise over 1000 document images. The results shaw high degree of confidence in region separation and extraction The main benefits include robust classification, shape independency and rapid computation.
Binary tree predictive coding uses a noncausal, shape-adaptive predictor to decompose an image into a binary tree of prediction errors and zero blocks. Fast compression performance is comparable with Joint Photographe...
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Binary tree predictive coding uses a noncausal, shape-adaptive predictor to decompose an image into a binary tree of prediction errors and zero blocks. Fast compression performance is comparable with Joint Photographers Expert Group (JPEG) for photographs, with GIF for graphics, and superior to the state of the art for composite images.
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