Showing papers by "William A. Pearlman published in 2006"

Three-Dimensional Wavelet-Based Compression of Hyperspectral Images

Abstract: This chapter proposed a three dimensional set partitioned embedded block coder for hyperspectral image compression The three dimensional wavelet transform automatically exploits inter-band dependence Two versions of the algorithm were implemented The integer filter implementation enables lossy-to-lossless compression, and the floating point filter implementation provides better performance for lossy representation Wavelet packet structure and bit shifting were applied on the integer filter implementation to make the transform approximately unitary

A Wavelet-Based Two-Stage Near-Lossless Coder

Abstract: In this paper, we present a two-stage near-lossless compression scheme. It belongs to the class of "lossy plus residual coding" and consists of a wavelet-based lossy layer followed by arithmetic coding of the quantized residual to guarantee a given Linfin error bound in the pixel domain. We focus on the selection of the optimum bit rate for the lossy layer to achieve the minimum total bit rate. Unlike other similar lossy plus lossless approaches using a wavelet-based lossy layer, the proposed method does not require iteration of decoding and inverse discrete wavelet transform in succession to locate the optimum bit rate. We propose a simple method to estimate the optimal bit rate, with a theoretical justification based on the critical rate argument from the rate-distortion theory and the independence of the residual error

Real-Time Video Transmission over MIMO OFDM Channels Using Space-Time Block Codes

Abstract: In this paper we consider the problem of faded wireless image and video transmission schemes over multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) channels that are energy and the bandwidth constrained. A computationally inexpensive analytic mean square error (MSE) distortion rate (D-R) estimator for progressive wavelet coders which generates an exact D-R (distortion rate) function for 2-D and 3-D SPIHT algorithm is utilized from our previous work. Using the D-R function, a joint source-channel coding scheme using optimal equal error protection (EEP) is presented. Both analytic and Monte-Carlo simulations are presented for image and video sources. A system that uses two transmit antennas and two receive antennas expends 12 dB less in energy per bit for the same performance as a SISO system. Our results are also significantly better than outage probability JSCC schemes used by other authors. The joint source-channel coding (JSCC) scheme demonstrates that MIMO OFDM can achieve real-time high quality video transmission in low energy regions and the system is robust against the delay spread and Doppler frequency shift.

Three-dimensional SPIHT Coding of Hyperspectral Images with Random Access and Resolution Scalability

Abstract: 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

Region of interest access with three-dimensional SBHP algorithm

Abstract: One interesting feature of image compression is support of region of interest (ROI) access, in which an image sequence can be encoded only once and then the decoder can directly extract a subset of the bitstream to reconstruct a chosen ROI of required quality. In this paper, we apply Three-dimensional Subband Block Hierarchical Partitioning (3-D SBHP), a highly scalable wavelet transform based algorithm, for volumetric medical image compression to support ROI access. The codeblock selection method by which random access decoding can be achieved is outlined and the performance empirically investigated. The experimental results show that there are a number of parameters that affect the effectiveness of ROI access, the most important being the size of the ROI size, code-block size, wavelet composition level, number of filter taps and target bit rate. Finally, one possible way to optimize ROI access performance is addressed.

On scalable lossless video coding based on sub-pixel accurate MCTF

Abstract: We propose two approaches to scalable lossless coding of motion video. They achieve SNR-scalable bitstream up to lossless reconstruction based upon the subpixel-accurate MCTF-based wavelet video coding. The first approach is based upon a two-stage encoding strategy where a lossy reconstruction layer is augmented by a following residual layer in order to obtain (nearly) lossless reconstruction. The key advantages of our approach include an 'on-the-fly' determination of bit budget distribution between the lossy and the residual layers, freedom to use almost any progressive lossy video coding scheme as the first layer and an added feature of near-lossless compression. The second approach capitalizes on the fact that we can maintain the invertibility of MCTF with an arbitrary sub-pixel accuracy even in the presence of an extra truncation step for lossless reconstruction thanks to the lifting implementation. Experimental results show that the proposed schemes achieve compression ratios not obtainable by intra-frame coders such as Motion JPEG-2000 thanks to their inter-frame coding nature. Also they are shown to outperform the state-of-the-art non-scalable inter-frame coder H.264 (JM) lossless mode, with the added benefit of bitstream embeddedness.

SPIHT algorithms using Depth First Search Algorithm with minimum memory usage

Abstract: This paper presents SPIHT and block-wise SPIHT algorithms where full depth first search algorithm is used to agglomerate significant bits at each bitplane. Search strategies used for SPIHT to date are more or less based on a breadth first search algorithm. The aim of this work is to minimize the final memory usage without paying additional overhead cost. DFS also brings benefits such as resolution scalability and a random access decodable bitstream.

Scalable three-dimensional sbhp algorithm with region of interest access and low-complexity

Abstract: A low-complexity three-dimensional image compression algorithm based on wavelet transforms and set-partitioning strategy is presented. The Subband Block Hierarchial Partitioning (SBHP) algorithm is modified and extended to three dimensions, and applied to every code block independently. The resultant algorithm, 3D-SBHP, efficiently encodes 3D image data by the exploitation of the dependencies in all dimensions, while enabling progressive SNR and resolution decompression and Region-of-Interest (ROI) access from the same bit stream. The code-block selection method by which random access decoding can be achieved is outlined.The resolution scalable and random access performances are empirically investigated. The results show 3D-SBHP is a good candidate to compress 3D image data sets for multimedia applications.

A wavelet-based two-stage near-lossless coder with L∞- error scalability

Abstract: We present a wavelet-based near-lossless coder with L∞-error scalability. The method presented consists of a wavelet-based lossy layer encoder followed by multiple stages of residual refinements for L∞-error scalability. We introduce a successive refinement scheme in L∞-error sense for residual layers reminiscent of popular set-partitioning algorithms for embedded coding. The initial near-lossless error bound is attained by our previously proposed two-stage scheme which determines the bit-rate for the lossy layer 'on-the-fly' without any iteration. The resulting residual which is defined by the difference between the original and the initial near-lossless reconstruction is then further refined in L∞-error sense up to lossless reconstruction. This scheme provides a combination of L 2 -error embedded lossy reconstruction up to an automatically determined high-fidelity plus optional layers of scalable L∞-error. This may turn out to be particularly useful for scalable archival applications where the fidelity of reconstructions on the high-bit end needs to be strictly controlled.

Enhancement of Video Quality for Energy Constrained Cellular Applications

Abstract: In this paper we consider the problem of faded wireless image and video transmission schemes under energy transmission constraints. An example of such a constrained system experiencing Rayleigh fading is code division multiple access (CDMA) where power control is used. We imposed on the average energy transmitted per an image or image sequence. A computationally inexpensive analytic mean square error (MSB) distortion rate (D-R) estimator for progressive wavelet coders which generates an exact distortion rate (D-R) function for 2-D and 3-D SPIHT algorithm is utilized from our previous research. Using the D-R function, the expected mean square error(MSE) at the receiver is minimized by optimally assigning the energy and parity allocation per each transmission block among the packets. A gain of 1.09 dB relative to optimal equal error protection (EEP) is obtained by varying both energy and parity among the transmission blocks. The results can be used to to increase image and video quality in CDMA systems.