Papers by William Pearlman
2000 IEEE International Conference on Acoustics, Speech, and Signal Processing. Proceedings (Cat. No.00CH37100)
ABSTRACT
[Proceedings] ICASSP 91: 1991 International Conference on Acoustics, Speech, and Signal Processing, 1991
An algorithm given by R.P. Rao (see Proc. IEEE Inter. Telecomm. Symp., Sept. 1990) for multirate ... more An algorithm given by R.P. Rao (see Proc. IEEE Inter. Telecomm. Symp., Sept. 1990) for multirate vector quantization is used for coding image pyramids. The algorithm, called alphabet- and entropy-constrained vector quantization (AECVQ), operates by optimally choosing sub-codebooks from a large generic codebook. In terms of performance and complexity, AECVQ equals the best single-rate VQ. Excellent results at 1 b/p
International Conference on Acoustics, Speech, and Signal Processing
An image coding system is proposed in which hexag-onally sampled images are decomposed into subba... more An image coding system is proposed in which hexag-onally sampled images are decomposed into subbands that are selective in both frequency and orientation. Nine high frequency bands each of one octave and 60 degrees of angular orientation are built on a pyramidal ...
Synthesis Lectures on Image, Video, and Multimedia Processing, 2013
This book explains the stages necessary to create a wavelet compression system for images and des... more This book explains the stages necessary to create a wavelet compression system for images and describes state-of-the-art systems used in image compression standards and current research. It starts with a high level discussion of the properties of the wavelet transform, especially the decomposition into multi-resolution subbands. It continues with an exposition of the null-zone, uniform quantization used in most subband coding systems and the optimal allocation of bitrate to the different subbands. Then the image compression systems of the FBI Fingerprint Compression Standard and the JPEG2000 Standard are described in detail. Following that, the set partitioning coders SPECK and SPIHT, and EZW are explained in detail and compared via a fictitious wavelet transform in actions and number of bits coded in a single pass in the top bit plane. The presentation teaches that, besides producing efficient compression, these coding systems, except for the FBI Standard, are capable of writing bit streams that have attributes of rate scalability, resolution scalability, and random access decoding. Many diagrams and tables accompany the text to aid understanding. The book is generous in pointing out references and resources to help the reader who wishes to expand his knowledge, know the origins of the methods, or find resources for running the various algorithms or building his own coding system.
The International Series in Engineering and Computer Science
Embedded zerotree wavelet (EZW) coding, introduced by J. M. Shapiro, is a very effective and comp... more Embedded zerotree wavelet (EZW) coding, introduced by J. M. Shapiro, is a very effective and computationally simple technique for image compression. Here we offer an alternative explanation of the principles of its operation, so that the reasons for its excellent performance can be better understood. These principles are partial ordering by magnitude with a set partitioning sorting algorithm, ordered bit
In this paper, we present the OB-SPECK algorithm (objectbased set partitionedembedded block coder... more In this paper, we present the OB-SPECK algorithm (objectbased set partitionedembedded block coder) for wavelet coding of arbitrary shaped video objects. Based on the SPECK algorithm introduced in [1], the shape information of the video object in the wavelet domain is integrated into the coding process for efficient coding of a video object of arbitrary shape. The whole coding system is a motion prediction coding system. First, the object in inter frame is predicted by the blockbased motion estimation and compensation; then the video object (in intra frame) and motion residue (in inter frame) are transformed by the object-based wavelet transform, which applies a proper sampling method so that the number of wavelet coefficients is the same as that of the original object and the spatial correlation within the object is preserved. Finally, the wavelet coefficients are encoded by the OB-SPECK algorithm. The proposed scheme achieves high coding efficiency and preserves the features of an embedded bitstream, low computational complexity and exact bitrate control.
Multimedia Signal Processing, 1998
This paper proposes an efficient, low complexity audio coder based on the SPIHT (set partitioning... more This paper proposes an efficient, low complexity audio coder based on the SPIHT (set partitioning in hierarchical trees) coding algorithm , which has achieved notable success in still image coding. A wavelet packet transform is used to decompose the audio signal into 29 frequency subbands corresponding roughly to the critical subbands of the human auditory system. A psychoacoustic model, which,
Applications of Digital Image Processing XIII, 1990
A recently introduced tree growth algorithm the Marginal Returns (MR) algorithm is used to grow m... more A recently introduced tree growth algorithm the Marginal Returns (MR) algorithm is used to grow multiple rate tree structured vector quantizers for the pyramid coding of hexagonally sampled images. The use of a structured multi-rate code book solves two problems that normally arise in vector quantization of subbands. The multiple rate code book can operate over a wide range of rates thus dispensing with the need to transmit the code book as overhead while the tree structure reduces the search complexity. Search complexity is a crucial issue even in low rate pyramid coding since subbands with more information content are coded at high rates. In addition the design technique makes it possible to tune the coder to the spectral properties of the image by optimally allocating rate to the different subbands. It has been shown in an earlier paper that the Marginal Returns algorithm yields code books that are optimal for sources that meet the law of diminishing marginal returns. However even for sources that do not satisfy these conditions the algorithm gives coders that perform close to the optimal. Image coding results at rates below 1 bpp are presented.
International Conference on Image Processing, Sep 10, 2000
This paper describes a low-memory cache efficient Hybrid Block Coder (HBC) for images in which an... more This paper describes a low-memory cache efficient Hybrid Block Coder (HBC) for images in which an image subband decomposition is partitioned into a combination of spatial blocks and subband blocks, which are independently coded. Spatial blocks contain hierarchical trees spanning subband levels, and are each encoded using the SPIHT algorithm. Subband blocks contain a block of coefficients from within a single subband, and are each encoded by the SPECK algorithm. The decomposition may have the dyadic or a wavelet packet structure. Rate is allocated amongst the sub-bitstreams produced for each block and they are packetized. The partitioning structure supports resolution embedding. The final bitstream may be progressive in fidelity or in resolution.
It is demonstrated in this paper that the encoding complexity advantage of a variable-length tree... more It is demonstrated in this paper that the encoding complexity advantage of a variable-length tree-structured vector quantizer (VLTSVQ) can be enhanced by encoding low dimensional subvectors of a source vector instead of the source vector itself at the nodes of the tree structure without significantly sacrificing coding performance. The greedy tree growing algorithm for the design of such a vector quantizer codebook is outlined. Different ways of partitioning the source vector into its subvectors and several criteria of interest for selecting the appropriate subvector for making the encoding decision at each node are discussed. Techniques of tree pruning and resolution reduction are applied to obtain improved coding performance at the same low encoding complexity. Application of an orthonormal transformation such as KLT or subband tranformation to the source and the implication of defining the subvectors from orthogonal subspaces are also discussed. Finally simulation results on stil...
Proceedings 2003 International Conference on Image Processing (Cat. No.03CH37429)
In this paper, we investigate region-based embedded wavelet compression methods and introduce reg... more In this paper, we investigate region-based embedded wavelet compression methods and introduce region-based extensions of the Set Partitioning In Hierarchical Trees (SPIHT) and the Set Partitioning Embedded bloCK (SPECK) coding algorithms applied to the breast region of digital mammograms. We have compared these region-based extensions, called OB-SPIHT and OB-SPECK, against the original SPI-HT and the new standard JPEG 2000 on five digital mammograms compressed at rates ranging from 0.1 to 1.0 bits per pixel (bpp). Distortion was evaluated for all images and compression rates by the Peak Signal-to-Noise Ratio (PSNR). A comparison applying SPIHT and JPEG 2000 to the same set of images with the background pixels fixed to zero was also carried out. For digital mammography, region-based compression methods represent an improvement in compression efficiency from full-image methods, also providing the possibility of encoding multiple regions of interest.
Digital Signal Compression
SPIE Proceedings, 1989
A hexagonally sampled image is split into a low pass band and nine pass bands of one octave width... more A hexagonally sampled image is split into a low pass band and nine pass bands of one octave width and sixty degrees angular orientation. The conditions to be satisfied by the filter banks for perfect reconstruction are presented. The human visual system's response to stimuli at differing spatial frequencies is then employed to shape the coding noise spectrum. Rate is allocated under a frequency weighted mean squared error distortion measure. A framework is presented for doing this employing either the power spectral density of the image or the variance of the subbands. Both adaptive and non-adaptive entropy coding simulations are carried out under a Laplacian source distribution. Transparent coding results are presented at rates below 1 bit per pixel.
IEEE Transactions on Image Processing, 1992
The authors consider the encoding of image subbands with a tree code that is asymptotically optim... more The authors consider the encoding of image subbands with a tree code that is asymptotically optimal for Gaussian sources and the mean squared error (MSE) distortion measure. They first prove that optimal encoding of ideally filtered subbands of a Gaussian image source achieves the rate distortion bound for the MSE distortion measure. The optimal rate and distortion allocation among the subbands is a by-product of this proof. A bound is derived which shows that subband coding is closer than full-band coding to the rate distortion bound for a finite length sequence. The tree codes are then applied to encode the image subbands, both nonadaptively and adaptively. Since the tree codes are stochastic and the search of the code tree is selective, a relatively few reproduction symbols may have an associated squared error a hundred times larger than the target for the subband. Correcting these symbols through a postcoding procedure improves the signal-to-noise ratio and visual quality significantly, with a marginal increase in total rate.
IEEE Transactions on Communications, 1990
A transform trellis coding scheme is used to encode images at rates below 1 b/pel, resulting in h... more A transform trellis coding scheme is used to encode images at rates below 1 b/pel, resulting in high SNR values and very good subjective performance. A discrete cosine transform (DCT) is used to decorrelate the data samples, and a trellis encoder is used to encode the transformed coefficients. To overcome image nonstationarity, a clustering algorithm is used to segment the transformed image into distinct regions and a separate trellis diagram is then constructed for each cluster. To further improve the image quality, particularly to reduce the blocking effect, a scalar quantizer is used to quantize large-magnitude coefficients of the error image in the transform domain. The performance of the proposed scheme is found to be better than that of other recently reported schemes
Foundations and Trends® in Signal Processing, 2007
The purpose of this two-part monograph is to present a tutorial on set partition coding, with emp... more The purpose of this two-part monograph is to present a tutorial on set partition coding, with emphasis and examples on image wavelet transform coding systems, and describe their use in modern image coding systems. Set partition coding is a procedure that recursively splits groups of integer data or transform elements guided by a sequence of threshold tests, producing groups of elements whose magnitudes are between two known thresholds, therefore, setting the maximum number of bits required for their binary representation. It produces groups of elements whose magnitudes are less than a certain known threshold. Therefore, the number of bits for representing an element in a particular group is no more than the base-2 logarithm of its threshold rounded up to the nearest integer. SPIHT (Set Partitioning in Hierarchical Trees) and SPECK (Set Partitioning Embedded blocK) are popular state-of-the-art image coders that use set partition coding as the primary entropy coding method. JPEG2000 and EZW (Embedded Zerotree Wavelet) use it in an auxiliary manner. Part I elucidates the fundamentals of set partition coding and explains the setting of thresholds and the block and tree modes of partitioning. Algorithms are presented for the techniques of AGP (Amplitude and Group Partitioning), SPIHT, SPECK, and EZW. Numerical examples are worked out in detail for the latter three techniques. Part II describes various wavelet image coding systems that use set partitioning primarily, such as SBHP (Subband Block Hierarchical Partitioning), SPIHT, and EZBC (Embedded Zero-Block Coder). The basic JPEG2000 coder is also described. The coding procedures and the specific methods are presented both logically and in algorithmic form, where possible. Besides the obvious objective of obtaining small file sizes, much emphasis is placed on achieving low computational complexity and desirable output bitstream attributes, such as embeddedness, scalability in resolution, and random access decodability.
2006 Fortieth Asilomar Conference on Signals, Systems and Computers, 2006
With the increase of remote sensing images, fast access to some features of the image is becoming... more With the increase of remote sensing images, fast access to some features of the image is becoming critical. This access could be some part of the spectrum, some area of the image, high spatial resolution. An adaptation of 3D-SPIHT image compression algorithm is presented to allow random access to some part of the image, whether spatial or spectral. Resolution scalability is also available, enabling the decoding of different resolution images from the compressed bitstream of the hyperspectral data. Final spatial and spectral resolutions are chosen independently. From the same compressed bitstream, various resolutions and quality images can be extracted while reading a minimum amount of bits from the coded data. All this is done while reducing the memory necessary during the compression.
Visual Communications and Image Processing 2004, 2004
Set Partitioned Embedded bloCK coder (SPECK) has been found to perform comparable to the best-kno... more Set Partitioned Embedded bloCK coder (SPECK) has been found to perform comparable to the best-known still grayscale image coders like EZW, SPIHT, JPEG2000 etc. In this paper, we first propose Color-SPECK (CSPECK), a natural extension of SPECK to handle color still images in the YUV 4:2:0 format. Extensions to other YUV formats are also possible. PSNR results indicate that CSPECK is among the best known color coders while the perceptual quality of reconstruction is superior than SPIHT and JPEG2000. We then propose a moving picture based coding system called Motion-SPECK with CSPECK as the core algorithm in an intra-based setting. Specifically, we demonstrate two modes of operation of Motion-SPECK, namely the constant-rate mode where every frame is coded at the same bit-rate and the constant-distortion mode, where we ensure the same quality for each frame. Results on well-known CIF sequences indicate that Motion-SPECK performs comparable to Motion-JPEG2000 while the visual quality of the sequence is in general superior. Both CSPECK and Motion-SPECK automatically inherit all the desirable features of SPECK such as embeddedness, low computational complexity, highly efficient performance, fast decoding and low dynamic memory requirements. The intended applications of Motion-SPECK would be high-end and emerging video applications such as High Quality Digital Video Recording System, Internet Video, Medical Imaging etc.
Journal of the Optical Society of America, 1982
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Papers by William Pearlman