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Ultrasonic NDE image compression by transform and subband coding

NDT & E INTERNATIONAL 2004年第4期37卷 325-333页

作者： Zhang, GM Olofsson, T Stepinski, T Uppsala Univ Signals & Syst Grp S-75120 Uppsala Sweden

In this paper, two categories of transform coding and subband coding are comparatively studied for compressing ultrasonic NDE images. The data compression performance of the discrete cosine transform-, the Karhunen-Loeve transform-, and the discrete wavelet transform-based codecs are examined by being applied to ultrasonic NDE images. The effects of these compression methods on the analysis of ultrasonic information in compressed ultrasonic images are examined. Moreover, evaluation of the main elements in image coding system is performed to explore the important factors, which are worth paying more attention when developing a special image compression technique for ultrasonic NDE images. (C) 2003 Elsevier Ltd. All rights reserved.

关键词： ultrasonic image non-destructive evaluation transform coding subband coding

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Comparison Analysis of a Biomedical Image for Compression Using Various transform coding Techniques

Comparison Analysis of a Biomedical Image for Compression Us...

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IEEE International Advance Computing Conference, IACC

作者： K.N. Shruthi B.M. Shashank Y. Saikrishna Saketh H.S. Prasantha S. Sandya Dept. of ECE Nitte Meenakshi Institute of Technology Bengaluru India

The theme work presented in this paper is adetailed analysis of various transforms like Discrete Cosinetransform, Singular Value Decomposition, Discrete Hadamardtransform, Slant transform, Discrete Haar transform whichare applied to a set of considered biomedical images to achieveimage compression. The operations on images are performedin transform domain where the DC coefficients are stored andtruncation operation is performed by setting correspondingthreshold to achieve desired PSNR to maintain the quality ofreconstruction. In this paper, the biomedical images aresubjected to all compression schemes mentioned by settingPSNR to 25dB and 30dB. The reconstruction qualities for boththe results (25dB and 30dB) are tabulated and detailed analysisis done based on the quality of reconstruction which throwslight on optimal transform. The metrics used for analysis areMean Square Error, Peak Signal to Noise ratio, StructuralSimilarity Index, Compression ratio, Energy Compaction and Auto-Correlation.

关键词： Image coding Discrete cosine transforms Image reconstruction transform coding Biomedical imaging Compaction

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Phase modelling of speech excitation for low bit-rate sinusoidal transform coding

Phase modelling of speech excitation for low bit-rate sinuso...

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International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： Xiaoqin Sun F. Plante B.M.G. Cheetham K.W.T. Wong Department of Electrical Engineering and Electronics University of Liverpool Liverpool UK Martlesham Heath BT Laboratories Ipswich UK

Sinusoidal transform coding (STC) techniques model speech as the sum of sine-waves whose frequencies, amplitudes and phases are specified at regular intervals. To achieve a low-bit rate representation, only the spectral envelope is encoded and the phases are regenerated according to a minimum phase assumption. In this paper, the inaccuracy of the minimum phase model is demonstrated. It is shown that the phase spectra of decoded speech segments may be corrected using either the parameters of a Rosenberg pulse model or a second order all-pass filter. Experiments have shown that by applying this correction, the phase accuracy increases and the speech quality improves.

关键词： Speech coding transform coding Frequency Speech synthesis Decoding Power harmonic filters Speech analysis Sun Electronic mail Laboratories

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Adaptive discrete cosine transform coding with vector quantization for color images

Adaptive discrete cosine transform coding with vector quanti...

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International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： K. Aizawa H. Harashima H. Miyakawa Department of Electrical Engineering University of Tokyo Tokyo Japan

A new vector quantization scheme in discrete cosine transform domain, named DCT-VQ and its application to color image coding are described. In this scheme, DCT-domain is partitioned into vectors which are normalized and vector-quantized using universal vector quantizers designed with multidimensional Laplacian distribution. Adaptive coding scheme is also introduced to obtain better reconstruction of images. The color image coder employs the above scheme and encodes separately three components converted from R,G,B signals. The simulations have shown that adaptive DCT-VQ exhibits better performance than a conventional adaptive cosine transform coding with scalar quantization. The decomposition of DCT-block into vectors results in much less complex coder than a vector quantizer in original space domain.

关键词： Discrete cosine transforms Image coding Vector quantization Color Multidimensional systems Laplace equations Adaptive coding Image reconstruction Image converters transform coding

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Deblocking filters for block-based ICA transform coding

Deblocking filters for block-based ICA transform coding

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International Conference on Emerging Technologies, ICET

作者： Asim Munir Bushra Asghar Muhammad Nadeem Department of Computer Science International Islamic University Islamabad Pakistan

Deblocking is required when data rate of a video stream is low. Images taken from such video streams also contain blocking artifacts. Similarly, when the images are compressed by ICA (Independent Component Analysis) transform coding, the resultant decompressed images are blocky. This paper describes the outcome of applying deblocking filters on ICA decoded images by using two schemes namely, “deblocking filter for low bit rate MPEG-4 video” and “low complexity deblocking method for DCT coded video signals”, respectively. The experiment is conducted on three sets of images at different quantization parameter. According to the results, the deblocking filter of scheme1 provides better SNR ratio than that of scheme2.

关键词： Signal to noise ratio transform coding Filtering algorithms Image edge detection Discrete cosine transforms Low pass filters

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Adaptive transform coding with an adaptive block size (ATC-ABS)

Adaptive transform coding with an adaptive block size (ATC-A...

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International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： A. Sugiyama F. Hazu M. Iwadare T. Nishitani C&C Systems Research Laboratories NEC Corporation Limited Kawasaki Kanagawa Japan

A coding technique is presented for high-quality audio signals based on adaptive transform coding (ATC). Adaptive block size selection by the proposed algorithm ensures an appropriate block size resulting in improved SNR (signal-to-noise ratio) for a wide variety of source signals. A feedback approach, based on SNR, and a feedforward approach, based on interblock differences in input time-domain samples, to adaptive block size assignment are proposed and evaluated. Computer simulation results show that average segmental SNR by the feedback approach is improved by as much as 4.8 dB over the conventional fixed-block-size ATC. The feedforward approach is realized with much-simplified hardware; nevertheless, its SNR degradation from that by the feedback approach is 1.6 dB, even in the worst case. Both approaches are successful in pre-echo suppression to a satisfactory level. Time-domain aliasing cancellation has the potential to increase the superiority of the new algorithm.< >

关键词： transform coding Feedback Time domain analysis Signal to noise ratio Computer simulation Hardware Degradation

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Lowering frame-buffering requirements of 3-D wavelet transform coding of interactive video

Lowering frame-buffering requirements of 3-D wavelet transfo...

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IEEE International Conference on Image Processing

作者： H. Khalil A.F. Atiya S.I. Shaheen University of California Santa Barbara CA USA Pasadena CA USA Cairo University Giza Egypt

In this paper, we present a 3-D wavelet compression technique for image sequences in video conferencing applications. One of the main requirements for such applications is that the delay has to be within some acceptable limit. When applying wavelet decomposition in the temporal direction, we must store a large number of frames so that such a decomposition can be effective. But this translates into a correspondingly large algorithmic delay. A technique to avoid this obstacle will be proposed. The basic idea is to overlap the decomposition with previous frames that have already been transmitted and selectively transmitting only the new wavelet coefficients.

关键词： transform coding Video compression Image coding Videoconference Delay Wavelet transforms Filters Frequency Image sequences Internet

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Iris image compression using wavelets transform coding

Iris image compression using wavelets transform coding

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International Conference on Signal Processing and Integrated Networks (SPIN)

作者： Arnob Paul Tanvir Zaman Khan Prajoy Podder Rafi Ahmed M. Muktadir Rahman Mamdudul Haque Khan Department of ECE Institute of Engineering & Management (IEM) Kolkata India Department of ECE Khulna University of Engineering & Technology (KUET) Khulna Bangladesh

Iris recognition system for identity authentication and verification is one of the most precise and accepted biometrics in the world. Portable iris system mostly used in law enforcement applications, has been increasing more rapidly. The portable device, however, requires a narrow-bandwidth communication channel to transmit iris code or iris image. Though a full resolution of iris image is preferred for accurate recognition of individual, to minimize time in a narrow-bandwidth channel for emergency identification, image compression should be used to minimize the size of image. This paper has investigated the effects of compression particularly for iris image based on wavelet transformed image, using Spatial-orientation tree wavelet (STW), Embedded Zero tree Wavelet (EZW) and Set Partitioning in hierarchical trees (SPIHT), to identify the most suitable image compression. In this paper, Haar wavelet transform is utilized for image compression and image decomposition, by varying the decomposition level. The results have been examined in terms of Peak signal to noise ratio (PSNR), Mean square Error (MSE), Bit per Pixel Ratio (BPP) and Compression ratio (CR). It has been evidently found that wavelet transform is more effective in the image compression, as recognition performance is minimally affected and the use of Haar transform is ideally suited. CASIA, MMU iris database have been used for this purpose.

关键词： Image coding Iris recognition Wavelet transforms Databases transform coding Signal processing algorithms

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A High Throughput Processor Chip for transform and Quantization coding in H.264/AVC

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JOURNAL OF SIGNAL PROCESSING SYSTEMS FOR SIGNAL IMAGE AND VIDEO TECHNOLOGY 2013年第1期70卷 59-73页

作者： Manzano, Miguel A. Michell, Juan A. Ruiz, Gustavo A. Univ Cantabria Fac Ciencias Dpto Elect & Comp E-39005 Santander Spain

This paper presents an ASIC processor chip for real-time implementation of the computing of the complete process of forward transform, quantization, inverse transform, dequantization, and reconstruction of a 16 x 16 macroblock in full compliance with the H.264/AVC video coding standard. This processor is capable of processing 4 x 4 blocks without interruption, with a parallelism in the data-path of 16 data/cycle, in a pipeline architecture with the twofold aim of achieving high operation frequency and high throughput. To implement the four 4 x 4 transforms and two 2 x 2 transforms required in the H.264/AVC coding system, two configurable multitransform direct 2-D architectures are used, one for forward and another for inverse. Moreover, a reduction in hardware is achieved by reformulating of quantization and dequantization equations and appropriately adjusting the datapath bus widths. A prototype of this processor chip was fabricated in the HCMOS9 STMicroelectronics 130 nm standard cell technology. The latency for 16 x 16 macroblocks is 26 clock cycles in normal mode and 42 in Intra 16 x 16 mode with a maximum operating frequency of 280 MHz and a throughput of 4,480 Mpixels/s. As a result, our processor chip is able to support the UHDTV 7680 x 4320@60 Hz (3 G sample/s) format requirement.

关键词： H.264 Integer transform Quantization transform coding ASIC processor

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Low-complexity transform coding with integer-to-integer transforms

Low-complexity transform coding with integer-to-integer tran...

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International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： C.D. Giurcaneanu I. Tabus Signal Processing Laboratory Tampere University of Technology Tampere Finland

We propose the application of a new transform-based coding method in conjunction with Golomb-Rice (G-R) codes to lower significantly the complexity, which can be used in various applications, e.g. the multiple description coding. The theoretical evaluations predict no important loss in compression performance, while the complexity is considerably reduced. Since GR codes are very fast and well suited for exponentially decaying distributions, they were implemented during the last decade in image and audio compressors. In all these schemes, the selection of the code parameter is performed presuming Laplacian distribution of prediction errors. We derive the selection method for the GR code parameter also for the case of Gaussian inputs.

关键词： transform coding Laplace equations Signal processing Laboratories Performance loss Compressors Communication systems Robustness Entropy coding Yarn

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