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IEEE Games, Entertainment, Media Conference (GEM)

作者： Subramanyam, Shishir Cesar, Pablo Ctr Wiskunde & Informat Distributed & Interact Syst Amsterdam Netherlands

ISBN: (纸本)9781538663042

In recent years, Virtual Reality (VR) and Augmented Reality (AR) applications have seen a drastic increase in commercial popularity. Different representations have been used to create 3D reconstructions for AR and VR. Point clouds are one such representation that are characterized by their simplicity and versatility, making them suitable for real time applications. However, point clouds are unorganized and identifying redundancies to use for compressing them is challenging. For the compression of time varying or dynamic sequences it is critical to identify temporal redundancies that can be used to describe predictors and further compress streams of point clouds. We use a point cloud codec that encodes additional information in an enhancement layer. We propose adding inter prediction to the enhancement layer in order to gain further bit rate savings.

关键词： Point cloud compression octrees enhancement layer interframe coding

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A Lossless Compression Method for Medical Image Sequences Using JPEG-LS and interframe coding

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IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE 2009年第5期13卷 818-821页

作者： Miaou, Shaou-Gang Ke, Fu-Sheng Chen, Shu-Ching Chung Yuan Christian Univ Dept Elect Engn Chungli 32023 Taiwan

Hospitals and medical centers produce an enormous amount of digital medical images every day, especially in the form of image sequences, which requires considerable storage space. One solution could be the application of lossless compression. Among available methods, JPEG-LS has excellent coding performance. However, it only compresses a single picture with intracoding and does not utilize the interframe correlation among pictures. Therefore, this paper proposes a method that combines the JPEG-LS and an interframe coding with motion vectors to enhance the compression performance of using JPEG-LS alone. Since the interframe correlation between two adjacent images in a medical image sequence is usually not as high as that in a general video image sequence, the interframe coding is activated only when the interframe correlation is high enough. With six capsule endoscope image sequences under test, the proposed method achieves average compression gains of 13.3% and 26.3% over the methods of using JPEG-LS and JPEG2000 alone, respectively. Similarly, for an MRI image sequence, coding gains of 77.5% and 86.5% are correspondingly obtained.

关键词： interframe coding JPEG-LS lossless compression medical image sequences

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Effective Lossless Compression for Medical Image Sequences Using Composite Algorithm

Effective Lossless Compression for Medical Image Sequences U...

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International Conference on Circuits, Power and Computing Technologies

作者： M. Ferni Ukrit G.R. Suresh Research Scholar Sathyabama University Professor Easwari Engineering College

ISBN: (纸本)9781467349215

Medical image compression is unavoidable due to large amount of storage space or high bandwidth for communication in its original form. In hospitals sequence of images are produced which are much correlated. Hence lossless image compression technique is required. To exploit the correlation a new algorithm is proposed in- this paper. The proposed compression method combines Super-Spatial Structure Prediction with interframe coding to achieve higher compression ratio. Initially the Super-Spatial Structure Prediction algorithm is applied with the fast block-matching process which includes Diamond Search method. To further increase the compression ratio we propose a new scheme Head Code Compression. Experimental results of our proposed Composite algorithm for medical image sequences achieve 25% more reduction than the prior arts.

关键词： Lossless Compression Medical Image Sequences Super-Spatial Structure Prediction MEMC interframe coding JPEG-LS CALIC Head Code Compression

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Fast intermode decision algorithm based on contextual mode and priority information for H.264/AVC video encoding system

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OPTICAL ENGINEERING 2011年第11期50卷 117403-117403页

作者： Jung, Hyun-Ki Kim, Hyo-Sung Kim, Byung-Gyu Kim, Chang-Ki Yoo, Jeong-Ju SunMoon Univ Dept Comp Engn Chungnam 366708 South Korea ETRI Smart Televis TV Res Dept Seoul South Korea

The recent H.264/AVC video coding standard provides a higher coding efficiency than previous standards. H.264/AVC achieves a bit rate saving of more than 50% with many new technologies, but it shows very heavy computational complexity. In this paper, a fast mode decision scheme for interframe coding is proposed to reduce the computational complexity for H.264/AVC video encoding system. To reduce the block mode decision complexity in interframe coding, we use the contextual information based on the co-located and neighboring macroblocks (MBs) to detect a proper MB that can be stopped early. Then, for the current MB, a priority information of the context is suggested for adding more mode types adaptively. The proposed algorithm shows the average speed-up factors of 59.11 to 77.41% for various sequences with a negligible bit increment and a minimal loss of image quality, in JM reference softwares. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3647552]

关键词： H.264/AVC video video coding interframe coding priority-based mode decision

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New Rate Distortion Bounds for Natural Videos Based on a Texture Dependent Correlation Model in the Spatial-Temporal Domain

New Rate Distortion Bounds for Natural Videos Based on a Tex...

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Annual Allerton Conference on Communication, Control, and Computing

作者： Jing Hu Jerry D. Gibson Department of Electrical and Computer Engineering University of California

ISBN: (纸本)9781424429257

We revisit the classic problem of developing a correlation model for natural videos and studying their theoretical rate distortion bounds. We propose the correlation coefficient of two pixels in two nearby video frames as the product of the spatial correlation coefficient of these two pixels, as if they were in the same frame, and a variable to quantify the temporal correlation between these two video frames. The spatial correlation model for pixels within one video frame is a conditional correlation model. The conditioning is on local texture and the optimal parameters can be calculated for a specific video with a mean absolute error (MAE) usually smaller than 5%. We use this conditional correlation model to calculate the conditional rate distortion function when universal side information on local texture is available at both the encoder and the decoder. We demonstrate that this side information, when available, can save as much as 1 bit per pixel for a single video frame and 0.7 bits per pixel for multiple video frames. This rate distortion bound with local texture information taken into account while making no assumptions on coding, is shown indeed to be a valid lower bound with respect to the operational rate distortion curves of both intra-frame and inter-frame coding in AVC/H.264.

关键词： Rate distortion pixel Videotapes VIDEO FRAMES side information interframe coding Frame texture rate distortion function correlation coefficient (r) Bound

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Single and double frame coding of speech LPC parameters using a lattice-based quantization scheme

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IEEE TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING 2006年第5期14卷 1624-1632页

作者： Lahouti, Farshad Fazel, Ahmad Reza Safavi-Naeini, Amir H. Khandani, Amir K. Univ Tehran Dept Elect & Comp Engn Tehran Iran Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

A lattice-based scheme for the single-frame and the double-frame quantization of the speech line spectral frequency parameters is proposed. The lattice structure provides a low-complexity vector quantization framework, which is implemented using a trellis structure. In the single-frame scheme, the intraframe dependencies are exploited using a linear predictor. In the double-frame scheme, the parameters of two consecutive frames are jointly quantized and hence the interframe dependencies are also exploited. A switched scheme is also considered in which, lattice-based double-frame and single-frame quantization is performed for each two frame and the one which results in a lower distortion is chosen. Comparisons to the Split-VQ [13], the Multi-Stage VQ [12], the Trellis Coded Quantization [15], the interframe Block-Based Trellis Quantizer [17], and the interframe scheme used in IS-641 EFRC [26] and the GSM AMR codec [28] are provided. These results demonstrate the effectiveness of the proposed lattice-based quantization schemes, while maintaining a very low complexity. Finally, the issue of the robustness to channel errors is investigated.

关键词： CELP interframe coding intraframe coding lattice-based quantization LPC LSF quantization speech coding

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Quantization of LSF parameters using a trellis modeling

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IEEE TRANSACTIONS ON SPEECH AND AUDIO PROCESSING 2003年第5期11卷 400-412页

作者： Lahouti, F Khandani, AK Univ Waterloo Dept Elect & Comp Engn Coding & Signal Transmiss Lab Waterloo ON N2L 3G1 Canada

An efficient Block-based Trellis Quantization (BTQ) scheme is proposed for the quantization of the Line Spectral Frequencies (LSF) in speech coding applications. The scheme is based on the modeling of the LSF intraframe dependencies with a trellis structure. The ordering property and the fact that LSF parameters are bounded within a range is explicitly incorporated in the trellis model. BTQ search and design algorithms are discussed and an efficient algorithm for the index generation (finding the index of a path in the trellis) is presented. Also the Sequential Vector Decorrelation Technique is presented to effectively exploit the intraframe correlation of LSF parameters within the trellis. Based on the proposed Block-based. Trellis Quantizer, two intraframe schemes and one interframe scheme are proposed. Comparisons to the Split-VQ [13], the Trellis Coded Quantization of LSF parameters [15], and the Multi-Stage VQ [12], as well as the interframe scheme used in IS-641 EFRC [28] and the GSM AMR codec [29] are provided. These results demonstrate that the proposed BTQ schemes outperform the above systems.

关键词： addressing CELP interframe coding intraframe coding LPC LSF quantization quantizer design speech coding trellis modeling

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Application of leaky prediction to an interframe coding scheme

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Electronics and Communications in Japan (Part I: Communications) 1998年第4期80卷

作者： Makoto Fujimura Hideo Kuroda Akira Nakamura Faculty of Engineering Nagasaki University Nagasaki Japan 852

In existing interframe predictive coding schemes, prediction error is minimized when the prediction factor is the same as the interframe correlation; methods based on complete prediction (with a prediction factor of 1) thus do not achieve optimum prediction. interframe leaky prediction was used in an effort to solve this problem. In the leaky prediction method proposed here, the frame type is determined from the interframe correlation and the leaky prediction coefficient, resulting in more efficient interframe coding. Complete prediction is used for nonsignificant blocks, preventing the number of significant blocks from increasing. To eliminate errors, intraframe cyclic refresh was combined with leaky prediction, thus improving recovery of image quality. The new method is well suited to moving image coding in ATM systems. Software simulations demonstrate that the method is effective. © 1997 Scripta Technica, Inc. Electron Comm Jpn Pt 1, 80 (4): 20–28, 1996

关键词： interframe coding leaky prediction hierarchical coding

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Enhanced interframe coding based on morphological segmentation

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IEE PROCEEDINGS-VISION IMAGE AND SIGNAL PROCESSING 1997年第4期144卷 220-226页

作者： Czerepinski, PJ Bull, DR Univ Bristol Ctr Commun Res Image Commun Grp Bristol BS8 1UB Avon England

Morphological segmentation has been proposed as an attractive alternative to transform-based compression for interframe coding of digital video. Being a spatial approach, segmentation based coding eliminates the artefacts commonly associated with transform coding, such as ringing around sharp edges. One disadvantage of this method is that it can introduce spurious edges in the reconstructed video sequence. associated with the boundaries of the transmitted regions. The authors present a statistically derived smoothing algorithm that reduces this problem. In addition, a single-stage entropy coder for the update signal is proposed in place of the conventional two-stage algorithm. Comparisons are made between the performance of a traditional motion compensated DCT coder and segmentation based codecs (with and without smoothing) for CIF sequences at bit rates between 64 and 256 kbps. It is concluded that, at the bit rates under investigation, the segmentation based method yields improved subjective quality of the reconstructed video.

关键词： digital video interframe coding morphological segmentation transform coding smoothing algorithm

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Application of leaky prediction to an interframe coding scheme

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ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 1997年第4期80卷 20-28页

作者： Fujimura, M Kuroda, H Nakamura, A Faculty of Engineering Nagasaki University Nagasaki 852 Japan Fukui University Japan FACOM HITAC Ltd. Japan Nagasaki University Japan Inst. Electronics Info. and Commun. Information Processing Society Japan Kyushu Institute of Technology Kitakyushu Japan Faculty of Engineering Nagasaki University Japan Inst. Electronics Info. Commun. E. Inst. Television Engineers of Japan IEEE Japan Kyushu University Fukuoka Japan Department of Electronic Engineering Kumamoto Institute of Technology Japan Info. Processing Society of Japan Japan

In existing interframe predictive coding schemes, prediction error is minimized when the prediction factor is the same as the interframe correlation;methods based on complete prediction (with a prediction factor of 1) thus do not achieve optimum prediction. interframe leaky prediction was used in art effort to solve this problem. In the leaky prediction method proposed here, the frame type is determined from the interframe correlation and the leaky prediction coefficient, resulting in more efficient interframe ceding. Complete prediction is used for nonsignificant blocks, preventing the number of significant blocks from increasing. To eliminate errors, intraframe cyclic refresh was combined with leaky prediction, thus improving recovery of image quality. The new method is well suited to moving image coding in ATM systems. Software simulations demonstrate that the method is effective.

关键词： interframe coding leaky prediction hierarchical coding

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