Results 1  10
of
219
Quantization
 IEEE TRANS. INFORM. THEORY
, 1998
"... The history of the theory and practice of quantization dates to 1948, although similar ideas had appeared in the literature as long ago as 1898. The fundamental role of quantization in modulation and analogtodigital conversion was first recognized during the early development of pulsecode modula ..."
Abstract

Cited by 700 (12 self)
 Add to MetaCart
The history of the theory and practice of quantization dates to 1948, although similar ideas had appeared in the literature as long ago as 1898. The fundamental role of quantization in modulation and analogtodigital conversion was first recognized during the early development of pulsecode modulation systems, especially in the 1948 paper of Oliver, Pierce, and Shannon. Also in 1948, Bennett published the first highresolution analysis of quantization and an exact analysis of quantization noise for Gaussian processes, and Shannon published the beginnings of rate distortion theory, which would provide a theory for quantization as analogtodigital conversion and as data compression. Beginning with these three papers of fifty years ago, we trace the history of quantization from its origins through this decade, and we survey the fundamentals of the theory and many of the popular and promising techniques for quantization.
Sparse Geometric Image Representations with Bandelets
, 2004
"... This paper introduces a new class of bases, called bandelet bases, which decompose the image along multiscale vectors that are elongated in the direction of a geometric flow. This geometric flow indicates directions in which the image grey levels have regular variations. The image decomposition in ..."
Abstract

Cited by 161 (4 self)
 Add to MetaCart
This paper introduces a new class of bases, called bandelet bases, which decompose the image along multiscale vectors that are elongated in the direction of a geometric flow. This geometric flow indicates directions in which the image grey levels have regular variations. The image decomposition in a bandelet basis is implemented with a fast subband filtering algorithm. Bandelet bases lead to optimal approximation rates for geometrically regular images. For image compression and noise removal applications, the geometric flow is optimized with fast algorithms, so that the resulting bandelet basis produces a minimum distortion. Comparisons are made with wavelet image compression and noise removal algorithms.
Spacefrequency Quantization for Wavelet Image Coding
, 1997
"... Recently, a new class of image coding algorithms coupling standard scalar quantization of frequency coefficients with treestructured quantization (related to spatial structures) has attracted wide attention because its good performance appears to confirm the promised efficiencies of hierarchical re ..."
Abstract

Cited by 160 (15 self)
 Add to MetaCart
Recently, a new class of image coding algorithms coupling standard scalar quantization of frequency coefficients with treestructured quantization (related to spatial structures) has attracted wide attention because its good performance appears to confirm the promised efficiencies of hierarchical representation [1, 2]. This paper addresses the problem of how spatial quantization modes and standard scalar quantization can be applied in a jointly optimal fashion in an image coder. We consider zerotree quantization (zeroing out treestructured sets of wavelet coefficients) and the simplest form of scalar quantization (a single common uniform scalar quantizer applied to all nonzeroed coefficients), and we formalize the problem of optimizing their joint application and we develop an image coding algorithm for solving the resulting optimization problem. Despite the basic form of the two quantizers considered, the resulting algorithm demonstrates coding performance that is competitive (often...
Data compression and harmonic analysis
 IEEE Trans. Inform. Theory
, 1998
"... In this paper we review some recent interactions between harmonic analysis and data compression. The story goes back of course to Shannon’s R(D) theory... ..."
Abstract

Cited by 149 (24 self)
 Add to MetaCart
In this paper we review some recent interactions between harmonic analysis and data compression. The story goes back of course to Shannon’s R(D) theory...
An overview of the JPEG2000 still image compression standard
 Signal Processing: Image Communication
, 2002
"... In 1996, the JPEGcommittee began to investigate possibilities for a new still image compression standard to serve current and future applications. This initiative, which was named JPEG2000, has resulted in a comprehensive standard (ISO 154447ITUT Recommendation T.800) that is being issued in six pa ..."
Abstract

Cited by 86 (0 self)
 Add to MetaCart
In 1996, the JPEGcommittee began to investigate possibilities for a new still image compression standard to serve current and future applications. This initiative, which was named JPEG2000, has resulted in a comprehensive standard (ISO 154447ITUT Recommendation T.800) that is being issued in six parts. Part 1, in the same vein as the JPEG baseline system, is aimed at minimal complexity and maximal interchange and was issued as an International Standard at the end of 2000. Parts 2–6 define extensions to both the compression technology and the file format and are currently in various stages of development. In this paper, a technical description of Part 1 of the JPEG2000 standard is provided, and the rationale behind the selected technologies is explained. Although the JPEG2000 standard only specifies the decoder and the codesteam syntax, the discussion will span both encoder and decoder issues to provide a better
RateDistortion Optimized Mode Selection for Very Low Bit Rate Video Coding and the Emerging H.263 Standard
, 1995
"... This paper addresses the problem of encoder optimization in a macroblockbased multimode video compression system. An efficient solution is proposed in which, for a given image region, the optimum combination of macroblock modes and the associated mode parameters are jointly selected so as to minim ..."
Abstract

Cited by 83 (12 self)
 Add to MetaCart
This paper addresses the problem of encoder optimization in a macroblockbased multimode video compression system. An efficient solution is proposed in which, for a given image region, the optimum combination of macroblock modes and the associated mode parameters are jointly selected so as to minimize the overall distortion for a given bitrate budget. Conditions for optimizing the encoder operation are derived within a rateconstrained product code framework using a Lagrangian formulation. The instantaneous rate of the encoder is controlled by a single Lagrange multiplier that makes the method amenable to mobile wireless networks with timevarying capacity. When rate and distortion dependencies are introduced between adjacent blocks (as is the case when the motion vectors are differentially encoded and/or overlapped block motion compensation is employed), the ensuing encoder complexity is surmounted using dynamic programming. Due to the generic nature of the algorithm, it can be succ...
Brushlets: A Tool for Directional Image Analysis and Image Compression
, 1997
"... This paper is organized as follows. In the next section we review the construction of orthonormal windowed Fourier bases. This is followed in section III by a description of biorthogonal windowed Fourier bases. The new brushlet basis is given in section IV. A biorthogonal brushlet basis is presented ..."
Abstract

Cited by 76 (10 self)
 Add to MetaCart
This paper is organized as follows. In the next section we review the construction of orthonormal windowed Fourier bases. This is followed in section III by a description of biorthogonal windowed Fourier bases. The new brushlet basis is given in section IV. A biorthogonal brushlet basis is presented in section V. In section VI we describe the image compression algorithm based on a brushlet expansion of the image. Results of experiments are presented in Section VII
Ratedistortion optimized tree structured compression algorithms for piecewise smooth images
 IEEE Trans. Image Processing
, 2005
"... IEEE Transactions on Image Processing This paper presents novel coding algorithms based on tree structured segmentation, which achieve the correct asymptotic ratedistortion (RD) behavior for a simple class of signals, known as piecewise polynomials, by using an RD based prune and join scheme. Fo ..."
Abstract

Cited by 71 (16 self)
 Add to MetaCart
IEEE Transactions on Image Processing This paper presents novel coding algorithms based on tree structured segmentation, which achieve the correct asymptotic ratedistortion (RD) behavior for a simple class of signals, known as piecewise polynomials, by using an RD based prune and join scheme. For the one dimensional (1D) case, our scheme is based on binary tree segmentation of the signal. This scheme approximates the signal segments using polynomial models and utilizes an RD optimal bit allocation strategy among the different signal segments. The scheme further encodes similar neighbors jointly to achieve the correct exponentially decaying RD behavior � D(R) ∼ c02 −c1R � , thus improving over classic wavelet schemes. We also prove that the computational complexity of the scheme is of O (N log N). We then show the extension of this scheme to the two dimensional (2D) case using a quadtree. This quadtree coding scheme also achieves an exponentially decaying RD behavior, for the polygonal image model composed of a white polygon shaped object against a uniform black background, with low computational cost of O (N log N). Again, the key is an RD optimized prune and join strategy. Finally, we conclude with numerical results, which show that the proposed quadtree coding scheme outperforms JPEG2000 by about 1 dB for real images, like cameraman, at low rates of around 0.15 bpp.
Computationally efficient optimal power allocation algorithms for multicarrier communication systems
 IEEE Transactions on Communications
"... Abstract—In this paper, we present an optimal, computationally efficient, integerbit power allocation algorithm for discrete multitone modulation. Using efficient lookup table searches and a Lagrangemultiplier bisection search, our algorithm converges faster to the optimal solution than existing ..."
Abstract

Cited by 69 (0 self)
 Add to MetaCart
Abstract—In this paper, we present an optimal, computationally efficient, integerbit power allocation algorithm for discrete multitone modulation. Using efficient lookup table searches and a Lagrangemultiplier bisection search, our algorithm converges faster to the optimal solution than existing techniques and can replace the use of suboptimal methods because of its low computational complexity. Fast algorithms are developed for the data rate and performance margin maximization problems. Index Terms—Discrete multitone modulation, loading algorithm, multicarrier communication systems, power allocation. I.
Wavelet Packet Image Coding Using Spacefrequency Quantization
 IEEE Trans. Image Processing
, 1998
"... We extend our previous work on spacefrequency quantization (SFQ) [1] for image coding from wavelet transforms to the more general wavelet packet transforms [2]. The resulting wavelet packet coder offers an universal transform coding framework within the constraints of filter bank structures by allo ..."
Abstract

Cited by 61 (5 self)
 Add to MetaCart
We extend our previous work on spacefrequency quantization (SFQ) [1] for image coding from wavelet transforms to the more general wavelet packet transforms [2]. The resulting wavelet packet coder offers an universal transform coding framework within the constraints of filter bank structures by allowing joint transform and quantizer design without assuming a priori statistics of the input image. In other words, the new coder adaptively chooses the representation to suit the image and the quantization to suit the representation. Experimental results show that, for some image classes, our new coder gives excellent coding performance. 1 Introduction Recently, wavelet transforms have attracted considerable attention, especially with applications to image coding, due to their ability to provide attractive spacefrequency resolution tradeoffs for natural images [3, 4]. In addition to conventional scalar (or vector) quantization strategies that are common in subband coding [5], the hierarchi...