Ali Bilgin - Academia.edu (original) (raw)
Papers by Ali Bilgin
Remote visualization of volumetric images has gained importance over the past few years in medica... more Remote visualization of volumetric images has gained importance over the past few years in medical and industrial applications. Volume visualization is a computationally intensive process, often requiring hardware acceleration to achieve a real time viewing experience. One remote visualization model that can accomplish this would transmit rendered images (with dedicated hardware) from the server based on view-point requests from a
IEEE Transactions on Communications, 2005
AbstractA joint source/channel coding algorithm is proposed for the transmission of multiple ima... more AbstractA joint source/channel coding algorithm is proposed for the transmission of multiple image sources over memoryless channels. The proposed algorithm uses a quality scalable image coder to optimally allocate a limited bit budget among all the sources to achieve the ...
Magnetic Resonance in Medicine, 2005
There has been recent interest in using reversible integer wavelet transforms for image compressi... more There has been recent interest in using reversible integer wavelet transforms for image compression. These transforms allow both lossless and lossy decoding-by resolution and/or accuracy-using a single bitstream. We investigate the lossless and lossy performance of these transforms in the JPEG-2000 Verification Model O. The lossless compression performance of the presented method is comparable to JPEG-LS. The lossy performance is quite competitive with other efficient lossy compression methods
IEEE Transactions on Image Processing, 2003
With the increasing importance of heterogeneous networks and time-varying communication channels,... more With the increasing importance of heterogeneous networks and time-varying communication channels, fine scalability has become a highly desirable feature in both image and video coders. A single highly scalable bitstream can provide precise rate control for constant bitrate (CBR) traffic and accurate quality control for variable bitrate (VBR) traffic. We first propose two leaky-bucket rate allocation methods that provide constant quality video under buffer constraints. These methods can be used with all scalable coders. Moreover, we make use of one of these methods (DBRC) and extend it so that it can be used when multiple sequences are multiplexed over a single communications channel. The goal is to allocate the capacity of the channel between sequences to achieve constant quality across all sequences. Experimental results using Motion JPEG2000 demonstrate substantial benefits.
IEEE Signal Processing Letters, 2000
We attempt to quantify the coding gain due to parent-child dependencies in subband transforms.The... more We attempt to quantify the coding gain due to parent-child dependencies in subband transforms.These dependencies are generally credited for the excellent MSE performances ofzero-tree based compression algorithms such as EZW and SPIHT. Our experiments indicatethat this gain is signicantly smaller than what is widely believed at the time of this writing.EDICS: SPL.IP.1.1. The authors are with the Department of Electrical
Magnetic Resonance in Medicine, 2007
Three-point Dixon techniques achieve good lipid-water separation by estimating the phase due to f... more Three-point Dixon techniques achieve good lipid-water separation by estimating the phase due to field inhomogeneities. Recently it was demonstrated that the combination of an iterative algorithm (iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL)) with a fast spin-echo (FSE) three-point Dixon method yielded robust lipid-water decomposition. As an alternative to FSE, the gradient- and spin-echo (GRASE) technique has been developed for efficient data collection. In this work we present a method for lipid-water separation by combining IDEAL with the GRASE technique. An approach to correct for errors in the lipid-water decomposition caused by phase distortions due to the switching of the readout gradient polarities inherent to GRASE is presented. The IDEAL-GRASE technique is demonstrated in phantoms and in vivo for various applications, including pelvic, musculoskeletal, and (breath-hold) cardiac imaging.
Dept. of Elec. and Comp. Eng. Dept. of Elec. and Comp. Eng. University of Arizona, University of ... more Dept. of Elec. and Comp. Eng. Dept. of Elec. and Comp. Eng. University of Arizona, University of Arizona, San Diego State University, ... Tucson, AZ 85721 Tucson, AZ 85721 San Diego, CA 92182 ... E-mail: bilgin@ece.arizona.edu E-mail: mwm@ece.arizona.edu E-mail: abut@ ...
A method for joint sourcelchannel rate allocation for trans-mission of JPEGZOOO u2K) codestreams ... more A method for joint sourcelchannel rate allocation for trans-mission of JPEGZOOO u2K) codestreams over noisy chan-nels is proposed. The rate allocation method uses the BER statistics of different channel codes and the rate-distortion characteristics of the source generated by the J2K ...
A novel lossless medical image compression algorithm based on three-dimensional integer wavelet t... more A novel lossless medical image compression algorithm based on three-dimensional integer wavelet transforms and zerotree coding is presented. The EZW algorithm is extended to three dimensions and context-based adaptive arithmetic coding is used to improve its performance. The algorithm (3-D CB-EZW) efficiently encodes image volumes by exploiting the dependencies in all three dimensions, while enabling lossy and lossless compression from the same bitstream. Results on lossless compression of CT and MR images are presented, and compared to other lossless compression algorithms. The progressive performance of the 3-D CB-EZW algorithm is also compared to other lossy progressive coding algorithms. For representative images, the 3-D CB-EZW algorithm produced an average of 14% and 20% decrease in compressed file sizes for CT and MR images, respectively, compared to the best available 2-D lossless compression techniques
IEEE Transactions on Image Processing, 2007
A framework is proposed for iterative joint source-channel decoding of JPEG2000 codestreams. At t... more A framework is proposed for iterative joint source-channel decoding of JPEG2000 codestreams. At the encoder, JPEG2000 is used to perform source coding with certain error-resilience (ER) modes, and LDPC codes are used to perform channel coding. During decoding, the source decoder uses the ER modes to identify corrupt sections of the codestream and provides this information to the channel decoder. Decoding is carried out jointly in an iterative fashion. Experimental results indicate that the proposed method requires fewer iterations and improves overall system performance
IEEE Transactions on Medical Imaging, 2006
One of the goals of telemedicine is to enable remote visualization and browsing of medical volume... more One of the goals of telemedicine is to enable remote visualization and browsing of medical volumes. There is a need to employ scalable compression schemes and efficient client-server models to obtain interactivity and an enhanced viewing experience. First, we present a scheme that uses JPEG2000 and JPIP (JPEG2000 Interactive Protocol) to transmit data in a multi-resolution and progressive fashion. The server exploits the spatial locality offered by the wavelet transform and packet indexing information to transmit, in so far as possible, compressed volume data relevant to the clients query. Once the client identifies its volume of interest (VOI), the volume is refined progressively within the VOI from an initial lossy to a final lossless representation. Contextual background information can also be made available having quality fading away from the VOI. Second, we present a prioritization that enables the client to progressively visualize scene content from a compressed file. In our specific example, the client is able to make requests to progressively receive data corresponding to any tissue type. The server is now capable of reordering the same compressed data file on the fly to serve data packets prioritized as per the client's request. Lastly, we describe the effect of compression parameters on compression ratio, decoding times and interactivity. We also present suggestions for optimizing JPEG2000 for remote volume visualization and volume browsing applications. The resulting system is ideally suited for client-server applications with the server maintaining the compressed volume data, to be browsed by a client with a low bandwidth constraint
JPEG2000 is the latest ISO/IEC image compression standard. It is distinct from previous standards... more JPEG2000 is the latest ISO/IEC image compression standard. It is distinct from previous standards in that it is more than an input-output filter. JPEG2000 enables decompression of many image products from a single compressed file and offers several opportunities for compressed domain processing. This paper describes the feature set of the JPEG2000 compression standard, followed by a high level description of the algorithm
IEEE Transactions on Consumer Electronics, 2003
IEEE Transactions on Image Processing, 2000
Reversible integer wavelet transforms allow both lossless and lossy decoding using a single bitst... more Reversible integer wavelet transforms allow both lossless and lossy decoding using a single bitstream. We present a new fully scalable image coder and investigate the lossless and lossy performance of these transforms in the proposed coder. The lossless compression performance of the presented method is comparable to JPEG-LS. The lossy performance is quite competitive with other efficient lossy compression methods
Remote visualization of volumetric images has gained importance over the past few years in medica... more Remote visualization of volumetric images has gained importance over the past few years in medical and industrial applications. Volume visualization is a computationally intensive process, often requiring hardware acceleration to achieve a real time viewing experience. One remote visualization model that can accomplish this would transmit rendered images (with dedicated hardware) from the server based on view-point requests from a
IEEE Transactions on Communications, 2005
AbstractA joint source/channel coding algorithm is proposed for the transmission of multiple ima... more AbstractA joint source/channel coding algorithm is proposed for the transmission of multiple image sources over memoryless channels. The proposed algorithm uses a quality scalable image coder to optimally allocate a limited bit budget among all the sources to achieve the ...
Magnetic Resonance in Medicine, 2005
There has been recent interest in using reversible integer wavelet transforms for image compressi... more There has been recent interest in using reversible integer wavelet transforms for image compression. These transforms allow both lossless and lossy decoding-by resolution and/or accuracy-using a single bitstream. We investigate the lossless and lossy performance of these transforms in the JPEG-2000 Verification Model O. The lossless compression performance of the presented method is comparable to JPEG-LS. The lossy performance is quite competitive with other efficient lossy compression methods
IEEE Transactions on Image Processing, 2003
With the increasing importance of heterogeneous networks and time-varying communication channels,... more With the increasing importance of heterogeneous networks and time-varying communication channels, fine scalability has become a highly desirable feature in both image and video coders. A single highly scalable bitstream can provide precise rate control for constant bitrate (CBR) traffic and accurate quality control for variable bitrate (VBR) traffic. We first propose two leaky-bucket rate allocation methods that provide constant quality video under buffer constraints. These methods can be used with all scalable coders. Moreover, we make use of one of these methods (DBRC) and extend it so that it can be used when multiple sequences are multiplexed over a single communications channel. The goal is to allocate the capacity of the channel between sequences to achieve constant quality across all sequences. Experimental results using Motion JPEG2000 demonstrate substantial benefits.
IEEE Signal Processing Letters, 2000
We attempt to quantify the coding gain due to parent-child dependencies in subband transforms.The... more We attempt to quantify the coding gain due to parent-child dependencies in subband transforms.These dependencies are generally credited for the excellent MSE performances ofzero-tree based compression algorithms such as EZW and SPIHT. Our experiments indicatethat this gain is signicantly smaller than what is widely believed at the time of this writing.EDICS: SPL.IP.1.1. The authors are with the Department of Electrical
Magnetic Resonance in Medicine, 2007
Three-point Dixon techniques achieve good lipid-water separation by estimating the phase due to f... more Three-point Dixon techniques achieve good lipid-water separation by estimating the phase due to field inhomogeneities. Recently it was demonstrated that the combination of an iterative algorithm (iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL)) with a fast spin-echo (FSE) three-point Dixon method yielded robust lipid-water decomposition. As an alternative to FSE, the gradient- and spin-echo (GRASE) technique has been developed for efficient data collection. In this work we present a method for lipid-water separation by combining IDEAL with the GRASE technique. An approach to correct for errors in the lipid-water decomposition caused by phase distortions due to the switching of the readout gradient polarities inherent to GRASE is presented. The IDEAL-GRASE technique is demonstrated in phantoms and in vivo for various applications, including pelvic, musculoskeletal, and (breath-hold) cardiac imaging.
Dept. of Elec. and Comp. Eng. Dept. of Elec. and Comp. Eng. University of Arizona, University of ... more Dept. of Elec. and Comp. Eng. Dept. of Elec. and Comp. Eng. University of Arizona, University of Arizona, San Diego State University, ... Tucson, AZ 85721 Tucson, AZ 85721 San Diego, CA 92182 ... E-mail: bilgin@ece.arizona.edu E-mail: mwm@ece.arizona.edu E-mail: abut@ ...
A method for joint sourcelchannel rate allocation for trans-mission of JPEGZOOO u2K) codestreams ... more A method for joint sourcelchannel rate allocation for trans-mission of JPEGZOOO u2K) codestreams over noisy chan-nels is proposed. The rate allocation method uses the BER statistics of different channel codes and the rate-distortion characteristics of the source generated by the J2K ...
A novel lossless medical image compression algorithm based on three-dimensional integer wavelet t... more A novel lossless medical image compression algorithm based on three-dimensional integer wavelet transforms and zerotree coding is presented. The EZW algorithm is extended to three dimensions and context-based adaptive arithmetic coding is used to improve its performance. The algorithm (3-D CB-EZW) efficiently encodes image volumes by exploiting the dependencies in all three dimensions, while enabling lossy and lossless compression from the same bitstream. Results on lossless compression of CT and MR images are presented, and compared to other lossless compression algorithms. The progressive performance of the 3-D CB-EZW algorithm is also compared to other lossy progressive coding algorithms. For representative images, the 3-D CB-EZW algorithm produced an average of 14% and 20% decrease in compressed file sizes for CT and MR images, respectively, compared to the best available 2-D lossless compression techniques
IEEE Transactions on Image Processing, 2007
A framework is proposed for iterative joint source-channel decoding of JPEG2000 codestreams. At t... more A framework is proposed for iterative joint source-channel decoding of JPEG2000 codestreams. At the encoder, JPEG2000 is used to perform source coding with certain error-resilience (ER) modes, and LDPC codes are used to perform channel coding. During decoding, the source decoder uses the ER modes to identify corrupt sections of the codestream and provides this information to the channel decoder. Decoding is carried out jointly in an iterative fashion. Experimental results indicate that the proposed method requires fewer iterations and improves overall system performance
IEEE Transactions on Medical Imaging, 2006
One of the goals of telemedicine is to enable remote visualization and browsing of medical volume... more One of the goals of telemedicine is to enable remote visualization and browsing of medical volumes. There is a need to employ scalable compression schemes and efficient client-server models to obtain interactivity and an enhanced viewing experience. First, we present a scheme that uses JPEG2000 and JPIP (JPEG2000 Interactive Protocol) to transmit data in a multi-resolution and progressive fashion. The server exploits the spatial locality offered by the wavelet transform and packet indexing information to transmit, in so far as possible, compressed volume data relevant to the clients query. Once the client identifies its volume of interest (VOI), the volume is refined progressively within the VOI from an initial lossy to a final lossless representation. Contextual background information can also be made available having quality fading away from the VOI. Second, we present a prioritization that enables the client to progressively visualize scene content from a compressed file. In our specific example, the client is able to make requests to progressively receive data corresponding to any tissue type. The server is now capable of reordering the same compressed data file on the fly to serve data packets prioritized as per the client's request. Lastly, we describe the effect of compression parameters on compression ratio, decoding times and interactivity. We also present suggestions for optimizing JPEG2000 for remote volume visualization and volume browsing applications. The resulting system is ideally suited for client-server applications with the server maintaining the compressed volume data, to be browsed by a client with a low bandwidth constraint
JPEG2000 is the latest ISO/IEC image compression standard. It is distinct from previous standards... more JPEG2000 is the latest ISO/IEC image compression standard. It is distinct from previous standards in that it is more than an input-output filter. JPEG2000 enables decompression of many image products from a single compressed file and offers several opportunities for compressed domain processing. This paper describes the feature set of the JPEG2000 compression standard, followed by a high level description of the algorithm
IEEE Transactions on Consumer Electronics, 2003
IEEE Transactions on Image Processing, 2000
Reversible integer wavelet transforms allow both lossless and lossy decoding using a single bitst... more Reversible integer wavelet transforms allow both lossless and lossy decoding using a single bitstream. We present a new fully scalable image coder and investigate the lossless and lossy performance of these transforms in the proposed coder. The lossless compression performance of the presented method is comparable to JPEG-LS. The lossy performance is quite competitive with other efficient lossy compression methods