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In this work, we develop a novel robust scheme of two-dimensional unequal error protection (2D-UEP) for the H.264 scalable video coding (H.264/SVC) with a combined temporal and quality (SNR) scalability over packet-lossy networks. The proposed scheme combines error resilience techniques and importance measures in video coding. To avoid the waste of bits and obtain the best rate allocation, we develop...
In this paper, we explore the impact of frame rate and quantization on perceptual quality of a video. We propose to use the product of a spatial quality factor that assesses the quality of decoded frames without considering the frame rate effect and a temporal correction factor, which reduces the quality assigned by the first factor according to the actual frame rate. We find that the temporal correction...
In networked video applications where the sustainable bandwidths vary greatly among the receivers and in time, one must be able to code a video or adapt a precoded-bitstream to a wide range of bit rates. It is critical to choose appropriate frame size, frame rate and quantization stepsize (QS) to optimize the perceptual quality for a target bit rate. Furthermore, it is important to understand the...
Current trends suggest that the Pervasive systems should be adaptive and flexible. Many Message-Oriented Pervasive systems have been proposed to support on-line self-composition of services in reaction to changing contexts. However, most existing service composition mechanisms either do not consider user preferences or use proprietary typing systems. In this paper, we propose an extensible ontology-based...
The US military will use digital video compression for many different operations and applications. System requirements result in the need to transmit video streams within limited bandwidth, and often over harsh transmission environments. To deliver video with sufficient quality, the most modern video encoders and decoders (codecs) need to be employed with parameters optimized for high compression...
This paper investigates the impact of frame rate and quantization on the bit rate and perceptual quality of a scalable video with temporal and quality scalability. We propose a rate model and a quality model, both in terms of the quantization stepsize and frame rate. The quality model is derived from our earlier quality model in terms of the PSNR of decoded frames and frame rate. Both models are developed...
Wireless video multicast enables delivery of popular events to many wireless users in a bandwidth efficient manner. However, providing good and stable video quality to a large number of users with varying channel conditions remains elusive. In our previous work, we integrated layered video coding with cooperative communication to enable efficient and robust video multicast in infrastructure-based...
Video multicast over wireless local area networks (WLANs) faces many challenges due to varying channel conditions and limited bandwidth. A promising solution to this problem is the use of packet level forward error correction (FEC) mechanisms. However, the adjustment of the FEC rate is not a trivial issue due to the dynamic wireless environment. This decision becomes more complicated if we consider...
A lifting-based wavelet domain Wiener filter(LBWDMF) in image enhancement is proposed. Lifting schemes have emerged as a powerful method for implementing bi-orthogonal wavelet filters. The method transforms an image into the wavelet domain using lifting-based wavelet filters and then applies a Wiener filter in the wavelet domain and finally transforms the result into the spatial domain. LBWDMF not...
This paper investigates the perceptual quality of decoded video bitstreams after packet losses. We focus on low-resolution and low-bit rate video coded by the H.264/AVC encoder, and packet loss patterns likely in 3G wireless networks. We examine the impact of several factors on the perceptual quality, including the error length (the error propagation duration after a loss), the loss severity (measured...
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