660 research outputs found
Low power techniques for video compression
This paper gives an overview of low-power techniques proposed in the literature for mobile multimedia and Internet applications. Exploitable aspects are discussed in the behavior of different video compression tools. These power-efficient solutions are then classified by synthesis domain and level of abstraction. As this paper is meant to be a starting point for further research in the area, a lowpower hardware & software co-design methodology is outlined in the end as a possible scenario for video-codec-on-a-chip implementations on future mobile multimedia platforms
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Very low bit-rate video coding focusing on moving regions using three-tier arbitrary-shaped pattern selection algorithm
Very low bit-rate video coding using patterns to represent moving regions in macroblocks exhibits good potential for improved coding efficiency. Recently an Arbitrary Shaped Pattern Selection (ASPS) algorithm and its Extended version(EASPS) were presented, that used a dynamically extracted set of patterns, of the two different sizes, based on actual video content. These algorithms, like other pattern matching algorithms failed to capture a large number of active-region macroblocks (RMB) especially when the object moving regions is relatively larger in a video sequence. As the size of the moving object may vary, superior coding performance is achievable by using dynamically extracted patterns of a larger size. This paper, proposes a three-tier Arbitrary Shaped Pattern Selection (ASPS-3) algorithm that uses three different pattern sizes for very low bit ate coding. Experimental results show that ASPS-3 exhibits better performance compared with other pattern matching algorithms, including the low-bit rate video coding standard H.263
Robust and fast global motion estimation for arbitrarily shaped video objects in MPEG-4
Centre for Multimedia Signal Processing, Department of Electronic and Information EngineeringRefereed conference paper2004-2005 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
Priority search technique for MPEG-4 motion estimation of arbitrarily shaped video object
2001-2002 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
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Fuzzy image segmentation of generic shaped clusters
The segmentation performance of any clustering algorithm is very sensitive to the features in an image, which ultimately restricts their generalisation capability. This limitation was the primary motivation in our investigation into using shape information to improve the generality of these algorithms. Fuzzy shape-based clustering techniques already consider ring and elliptical profiles in segmentation, though most real objects are neither ring nor elliptically shaped. This paper addresses this issue by introducing a new shape-based algorithm called fuzzy image segmentation of generic shaped clusters (FISG) that incorporates generic shape information into the framework of the fuzzy c-means (FCM) algorithm. Both qualitative and quantitative analyses confirm the superiority of FISG compared to other shape-based fuzzy clustering methods including, Gustafson-Kessel algorithm, ring-shaped, circular shell, c-ellipsoidal shells and elliptic ring-shaped clusters. The new algorithm has also been shown to be application independent so it can be applied in areas such as video object plane segmentation in MPEG-4 based coding
A novel hexagonal search algorithm for fast block matching motion estimation
Authors of articles published in EURASIP Journal on Advances in Signal Processing are the copyright holders of their articles and have granted to any third party, in advance and in perpetuity, the right to use, reproduce or disseminate the article, according to the SpringerOpen copyright and license agreement (http://www.springeropen.com/authors/license)
Shape adaptive integer transform for coding arbitrarily shaped objects in H.264/AVC
The use of shape-adaptive transforms is a popular approach for coding arbitrarily shaped objects in image/video coding
due to their adaptability at object edges and low complexity. In this respect shape adaptive DCT (SA-DCT) and shape
adaptive DWT (SA-DWT) have been proposed in previous literature. The Integer Transform (IT), a derivative of the
4x4 DCT, has been adopted in the latest H.264/AVC standard for coding image blocks in residual data (texture). The
associated integer arithmetic guarantees fast and accurate coding/decoding. In this paper, we propose a novel Shape
Adaptive Integer Transform (SA-IT) which can be effectively used in future for enabling arbitrary shaped object coding
in H.264. Though Integer Transforms are a derivative of 4x4 DCTs, in H.264, to maintain integer arithmetic capability,
the post-and pre-scaling factors of transform process are integrated into the forward and inverse quantiser stages
respectively for reducing the total number of multiplications and avoiding the loss of accuracy. Thus SA-IT considerably
differs from SA-DCT and calls for novel design and implementation considerations based on combining those merits of
both SA-DCT and IT. We provide theoretical proofs and support them with experimental justifications
The aceToolbox: low-level audiovisual feature extraction for retrieval and classification
In this paper we present an overview of a software platform
that has been developed within the aceMedia project,
termed the aceToolbox, that provides global and local lowlevel feature extraction from audio-visual content. The toolbox is based on the MPEG-7 eXperimental Model (XM),
with extensions to provide descriptor extraction from arbitrarily shaped image segments, thereby supporting local descriptors reflecting real image content. We describe the architecture of the toolbox as well as providing an overview of the descriptors supported to date. We also briefly describe the segmentation algorithm provided. We then demonstrate the usefulness of the toolbox in the context of two different content processing scenarios: similarity-based retrieval in large collections and scene-level classification of still images
Hardware acceleration architectures for MPEG-Based mobile video platforms: a brief overview
This paper presents a brief overview of past and current hardware acceleration (HwA) approaches that have been proposed for the most computationally intensive compression tools of the MPEG-4 standard. These approaches are classified based on their historical evolution and architectural approach. An analysis of both evolutionary and functional classifications is carried out in order to speculate on the possible trends of the HwA architectures to be employed in mobile video platforms
Energy-efficient acceleration of MPEG-4 compression tools
We propose novel hardware accelerator architectures for the most computationally demanding algorithms of the MPEG-4 video compression standard-motion estimation, binary motion estimation (for shape coding), and the forward/inverse discrete cosine transforms (incorporating shape adaptive modes). These accelerators have been designed using general low-energy design philosophies at the algorithmic/architectural abstraction levels. The themes of these philosophies are avoiding waste and trading area/performance for power and energy gains. Each core has been synthesised targeting TSMC 0.09
μm TCBN90LP technology, and the experimental results presented in this paper show that the proposed cores improve upon the prior art
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