In a scalable video coding (SVC), spatial down/up-sampling of video sequences is an essential process for spatial scalability. We propose an arbitrary-ratio spatial down-sampling method based on the type-II DCT, with which down-sampling of H.264 SVC can be efficient. Simple windowing operation in the DCT domain is efficiently embedded in the proposed down-sampling method for aliasing reduction. A fast algorithm for arbitrary-ratio down-sampling is introduced with matrix decomposition and fast DCT. It achieves 80 % reduction of computation complexity in comparison with the direct matrix calculation.

When a video sequence is compressed with rate control for a constant bit rate (CBR) channel, the visual quality usually fluctuates according to image complexity. We introduced distortion models under the CBR condition to predict distortion during rate control. The paper also proposes a control method for improvement of visual quality in H.264 CBR condition. In the experiments, we analyzed the peak signal-to-noise ratio (PSNR), the variance of the PSNR, and the average difference of the PSNR between adjacent frames for various video sequences. Our method demonstrates a more stable visual quality without severe PSNR degradation.

Packet drops caused byresidueerrors(MAC-layer errors) can severely deteriorate the wireless video quality. Prior studies have shown that this loss of quality can be circumvented by using forward error correction (FEC) to recover information from the corrupted packets. The performance of FEC encoded video streaming is critically dependent upon the choice of source and channel coding rates. In practice, the wireless channel conditions can vary significantly, thus altering the optimal rate choices. Thus, it is essential to develop an architecture which can estimate the channel capacity and utilize this estimate for rate allocation. In this paper we develop such a framework. Our contributions consist of two parts. In the first part we develop a prediction framework that leverages the received packets' signal to silence ratio (SSR) indications and MAC-layer checksum as side information to predict the operational channel capacity. In the second part, we use this prediction framework for rate allocation. The optimal rate allocation is dependent upon thechannelcapacity, the distribution of the (capacity)predictionerrorand the rate-distortion (RD) characteristics of the video source. Consequently, we propose a framework that utilizes the aforementioned statistics for RD optimal rate adaptation. We exhibit the efficacy of the proposed scheme by simulations using actual 802.11b wireless traces, an RD model for the video source and an ideal FEC model. Simulations using source RD models derived from five different popular video codecs (including H.264), show that the proposed framework provides up-to 5-dB improvements in peak signal-to-noise ratio (PSNR) when compared with conventional rate-adaptive schemes.

Performance of cross-layer protocols that recommend the relay of corrupted packets to higher layers can be improved significantly by accurately inferring/predicting the bit error rate (BER) in the packets. In practice, higher layers observe the bits only after some hard decision. Hence physical layer link-quality indications, such as the signal strength of each individual bit, are not observable at higher layers. Therefore, it is essential to identify practically observable variables, which can be used for reasonably robust channel state inference/prediction (CSI/CSP). Here, inference specifically refers to estimating the BER in an already received packet, while prediction refers to anticipating the BER in a future packet. In this paper, we note that, in practical 802.11b devices, it is possible to acquire a Signal to Silence Ratio (SSR) indication and measure the background traffic intensity (p) on a per packet basis. This paper, thus presents a measurement-based study that analyzes the utility of SSR andpas side-information for CSI/CSP. In this work, we exploit the method of types to measure the robustness of the observable side-information. Our analysis and simulations based on an extensive set of actual 802.11b traces exhibit the practical utility of the considered observable variables.

MPEG is formalizing the MPEG-4 based IPMP (intellectual property management and protection), and is systematizing the scheme for MPEG-4 content and its copyright. In this paper, we propose an MPEG-4 IPMP authoring tool, using which the MPEG-4 content author can create protected MPEG-4 content and its copyright easily and conveniently according to the MPEG-4 IPMP standard. The proposed authoring system offers an intimate interface to the author and creates an IPMPed XMT (extensible MPEG-4 textual format) file that consists of a text format so that editing and correction of contents may be convenient. Also, this can create an IPMPed MP4 file that consists of a binary format for efficiency in content transmission and storage.

DRM (digital rights management) technologies support the protection of intellectual properties against illegal actions. Due the development of digital broadcasting technology and storage media such as PVR (personal video recorder), it is possible for the viewer to watch and to acquire digital broadcasting content of high quality. For digital broadcasting content, therefore, DRM technologies can be applicable in order to prohibit illegal usage by the viewer. We designed a protection and distribution service model for broadcast content in which the license is issued to the viewer who recorded it on his storage media.

Technical advance in creating, storing digital media in daily life enables computers to capture human life and remember it as people do. A critical point with digitizing human life is how to recall bits of experience that are associated by semantic information. This paper proposes a technique for structuring dynamic digital object based on MPEG-21 Digital Item (DI) in order to recall human’s memory and providing interactive TV service on family tree albuming system as one of its applications. DIs are a dynamically reconfigurable, uniquely identified, described by a descriptor language, logical unit for structuring relationship among multiple media resources. Digital Item Processing (DIP) provides the means to interact with DIs to remind context to user, with active properties where objects have executable properties. Each user can adapt DIs’ active properties to tailor the behavior of DIs to match his/her own specific needs. DIs’ technologies in Intellectual Property Management and Protection (IPMP) can be used for privacy protection. In the interaction between the social space and technological space, the internal dynamics of family life fits well sharing family albuming service via family television. Family albuming service can act as virtual communities builders for family members. As memory is shared between family members, multiple annotations (including active properties on contextual information) will be made with snowballing value.

Echo watermarking marks audio signals by adding an echo. The embedded signal is not additive noise but an audio signal having the same statistical and perceptual characteristics. The echo is even perceived as added resonance. Conventional echo watermarking techniques often exhibit inherent trade-offs between imperceptibility and robustness. A new echo embedding technique is proposed. The proposed method enables one to embed high energy echoes while the host audio quality is not deteriorated, so that it is robust to common signal processing modifications and resistant to tampering. This is possible due to echo kernels that are designed based on psychoacoustic analyses. Subjective and objective evaluations confirmed that the proposed method could improve the robustness without perceptible distortion.

A new echo embedding technique in audio watermarking is proposed. The proposed method enables one to embed large energy echoes while the host audio quality is not deteriorated, so that it is robust to common signal processing modifications and resistant to tampering. Practical issues such as parameter tuning and further schemes for robust detection under attacks are also described. Subjective and objective evaluations confirmed that the proposed method could improve the robustness without perceptible distortion.