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ABSTRACT: The use of realistic humanoid animations generated through motion capture (MoCap) technology is widespread across various 3-D applications and industries. However, the existing compression techniques for such representation often do not consider the implicit coherence within the anatomical structure of a human skeletal model and lacks portability for transmission consideration. In this paper, a novel concept virtual character animation image (VCAI) is proposed. Built upon a fuzzy clustering algorithm, the data similarity within the anatomy structure of a virtual character (VC) model is jointly considered with the temporal coherence within the motion data to achieve efficient data compression. Since the VCA is mapped as an image, the use of image processing tool is possible for efficient compression and delivery of such content across dynamic network. A modified motion filter (MMF) is proposed to minimize the visual discontinuity in VCA's motion due to the quantization and transmission error. The MMF helps to remove high frequency noise components and smoothen the motion signal providing perceptually improved VCA with lessened distortion. Simulation results show that the proposed algorithm is competitive in compression efficiency and decoded VCA quality against the state-of-the-art VCA compression methods, making it suitable for providing quality VCA animation to low-powered mobile devices.
IEEE Transactions on Multimedia 03/2011; · 1.93 Impact Factor
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IEEE 13th International Workshop on Multimedia Signal Processing (MMSP 2011), Hangzhou, China, October 17-19, 2011; 01/2011
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International Symposium on Circuits and Systems (ISCAS 2011), May 15-19 2011, Rio de Janeiro, Brazil; 01/2011
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IEEE Trans. Circuits Syst. Video Techn. 01/2011; 21:1476-1486.
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18th IEEE International Conference on Image Processing, ICIP 2011, Brussels, Belgium, September 11-14, 2011; 01/2011
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18th IEEE International Conference on Image Processing, ICIP 2011, Brussels, Belgium, September 11-14, 2011; 01/2011
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ABSTRACT: Scalable video coding technique has been desired for many years to fulfill the requirement of reliable transmission of video over heterogeneous networks. It allows for simple solutions in adaptation to network constraint and user capabilities by providing a full scalability including temporal, spatial and quality scalability. Various coding structures will dramatically affect the overall performance of the system. In this paper, we develop a new joint source and channel coding scheme for wireless broadcasting making use of H.264/SVC considering the various clients' statistics such as the accessing bandwidth and the error rate. First, an effective algorithm is carried out to distribute proper amount of source codes and channel codes to the base layer to guarantee that all the clients can receive the video with a minimum quality. Second, to deal with the burst packet loss, we propose to apply the unequal error protection (UEP) scheme on the enhancement layers using the interleaved packetization to make sure that all the lower layers can be decoded if an enhancement layer is correctly received. To maximize the system-defined utility function, fast algorithms are designed to dynamically allocate the source coding rate and the channel coding rate for the scalable bit-stream given the clients' distribution. Experiments are conducted to verify the performance of the proposed algorithm against the other two schemes, where equal error protection (EEP) and UEP schemes with different coding structures are employed. The results demonstrate the superiority of the proposed scheme and the improvement is up to 2 dB.
IEEE Transactions on Broadcasting 10/2010; · 1.70 Impact Factor
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ABSTRACT: Mobile-based landmark recognition is becoming increasingly appealing due to the proliferation of mobile devices coupled with improving processing techniques, imaging capability, and networking infrastructure. This article provides a general overview of existing mobile-based and nonmobile-based landmark recognition systems and their differences. We discuss content and context analysis and compare landmark classification methods. We also present the experimental results of our own mobile landmark recognition evaluations based on content analysis, context analysis, and integrated content-context analysis.
Intelligent Systems, IEEE 03/2010; · 2.15 Impact Factor
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ABSTRACT: In this paper, a novel encoding scheme for virtual character animation (VCA) is proposed. By representing each segment of motion information of a skeletal avatar as an image map, temporal coherence presented within the joints sequences of the VCA can now be exploited as spatial redundancies within an image using conventional image processing tools and standards to achieve efficient compression for the character animation sequences. Simulation results demonstrated that the proposed scheme achieve competitive rate-distortion performance compare to previously proposed SVCA scheme for virtual character animation sequences. The proposed scheme is suitable for providing VCA to low powered mobile devices requiring small data size while maintaining satisfactory visual quality at the client side.
Information, Communications and Signal Processing, 2009. ICICS 2009. 7th International Conference on; 01/2010
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ABSTRACT: The growing usage of mobile camera phones has led to proliferation of many mobile applications. Landmark recognition is one of the mobile applications that are gaining more attention in recent years. The main idea of the application is that a user will use a camera phone to capture the image of a landmark or building and then the system will analyze, identify, and inform the user the name of the captured landmark together with its related information. A new mobile landmark recognition method is proposed in this paper: first, a set of multi-scale patches are extracted from the landmark images. Discriminative patches of the images are then selected based on a Gaussian mixture model (GMM). A combination of color, texture and scale-invariant feature transform (SIFT) descriptors are then extracted from the selected patches. They are used to train support vector machine (SVM) classifiers for each category of landmark. Experimental results using a database of 4000 landmark images illustrate the effectiveness of the proposed method.
Information, Communications and Signal Processing, 2009. ICICS 2009. 7th International Conference on; 01/2010
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J. Visual Communication and Image Representation. 01/2010; 21:210-218.
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IEEE Trans. Circuits Syst. Video Techn. 01/2010; 20:829-837.
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IEEE Intelligent Systems. 01/2010; 25:48-57.
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Proceedings of the International Conference on Image Processing, ICIP 2010, September 26-29, Hong Kong, China; 01/2010
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Signal Processing Systems. 01/2010; 59:163-175.
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Signal Processing Systems. 01/2010; 59:139-141.
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ABSTRACT: This letter proposes a nonlinear L <sub>1</sub>-norm approach for joint image registration and super-resolution (SR). Image SR is the fusion of multiple low-resolution (LR) images to produce a high-resolution (HR) image. Conventional SR algorithms are sensitive to the initial registration error and outliers in the LR images. In view of this, we present a new SR method to address these problems using L <sub>1</sub>-norm optimization in joint image registration and HR image reconstruction. Experimental results show that the proposed method is effective in handling these issues in the HR image reconstruction.
IEEE Signal Processing Letters 12/2009; · 1.39 Impact Factor
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ABSTRACT: In this paper, a technique for transmitting level of details motion sequences for virtual character animation is proposed. We have demonstrated that by using progressive level of details (LOD) scheme on the motion capture information, efficient LOD representation of the skeleton motion can be obtained. The proposed virtual character encoder is scalable in nature providing a form of flexibility for the bit-stream to be partially decodable at any bit rate within the bit rate range to address the dynamic bandwidth constraint of a heterogeneous wireless network. Based on the structural characteristic of the virtual character, the packet will be delivered across dynamic channel condition to provide the viewer with the best reconstructed virtual character's motion quality.
Circuits and Systems, 2009. ISCAS 2009. IEEE International Symposium on; 06/2009
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ABSTRACT: Scalable video coding technique has been desired for many years to realize a reliable transmission of video over heterogeneous networks. In this paper, we present a new system of scalable video broadcasting over wireless networks. For each group of pictures, a number of quality layers are produced using scalable video coding. We design the channel protection schemes using the forward error correction codes for the base layer and the enhancement layers, respectively. Given the clients' distribution, we propose a novel algorithm to determine both the source coding bit-rate and the channel coding bit-rate for each layer to maximize a system-defined utility function. Experimental results can demonstrate the superior of the proposed scheme to other schemes and the improvement is up to 2 dB.
Circuits and Systems, 2009. ISCAS 2009. IEEE International Symposium on; 06/2009
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ABSTRACT: The growing usage of mobile devices has led to proliferation of many mobile applications. A growing trend in mobile applications is centered on mobile landmark recognition. It is a new mobile application that recognizes a captured landmark using the mobile device and retrieves related information. This paper will present a survey on mobile landmark recognition for information retrieval. A general overview of existing mobile landmark recognition systems will be summarized. The techniques and algorithms used in the literatures, including content analysis of landmarks and classification methods for recognition, will be described.
Mobile Data Management: Systems, Services and Middleware, 2009. MDM '09. Tenth International Conference on; 06/2009
