José Oliver

José Oliver
Universitat Politècnica de València | UPV · Department of Computer Engineering

About

25
Publications
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273
Citations

Publications

Publications (25)
Article
Full-text available
When comparing the performance of video coding approaches, evaluating different commercial video encoders, or measuring the perceived video quality in a wireless environment, Rate/distortion analysis is commonly used, where distortion is usually measured in terms of PSNR values. However, PSNR does not always capture the distortion perceived by a hu...
Conference Paper
Full-text available
Transmitting video over Vehicular Adhoc NETworks (VANETs) is a hard-to-manage task. This is due to VANET problems (attenuation, packet losses, changing topology, etc.) and video streaming high requirements. To find out the feasibility of video streaming over VANETs and which error resilience strategies can improve video quality, testing is necessar...
Conference Paper
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The 3D-DWT is a mathematical tool of increasing importance in those applications that require an efficient processing of volumetric info. Other applications like professional video editing, IPTV video surveillance applications, live event IPTV broadcast, multi-spectral satellite imaging, HQ video delivery, etc, would rather use 3D-DWT encoders to r...
Conference Paper
Full-text available
The 3D-DWT is a mathematical tool of increasing importance in those applications that require an efficient processing of volumetric info. However, the huge memory requirement of the algorithms that compute it is one of the main drawbacks in practical implementations. In this paper, we introduce a fast frame-based 3D-DWT video encoder with low memor...
Conference Paper
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Traditional embedded coding systems involve high complexity algorithms, requiring fast and expensive processors. In the last years, several authors have developed very fast and simple non-embedded wavelet encoders that are able to get reasonable good performance with reduced computing requirements. These encoders have lost the SNR scalability and p...
Article
Full-text available
Providing quality-of-service (QoS) in wireless ad hoc networks is an intrinsically complex task due to node mobility, distributed channel access, and fading radio signal effects. This goal can be successfully accomplished only through the cooperation of the different protocol layers involved. In this paper we propose a novel QoS architecture that i...
Article
Intra-video coding is a common way to process video material for applications like professional video editing systems, digital cinema, video surveillance applications, multi-spectral satellite imaging, HQ video delivery, etc. Most practical intra-coding systems employ JPEG encoders due to their simplicity, low coding delay and low memory requiremen...
Article
Full-text available
In this paper, a new algorithm to efficiently compute the two-dimensional wavelet transform is presented. This algorithm aims at low memory consumption and reduced complexity, meeting these requirements by means of line-by-line processing. In this proposal, we use recursion to automatically place the order in which the wavelet transform is computed...
Conference Paper
Full-text available
Distributed Video Coding (DVC) is a promising coding solution for some emerging applications, where the encoder complexity, power consumption or memory requirements are constraint the system resources. Current approaches to DVC focus on improving the performance of the Wyner- Ziv coding by improving the quality of the reconstructed side information...
Conference Paper
Intra video coding is a common way to process video material for applications like professional video editing systems, digital cinema, video surveillance applications, multispectral satellite imaging, HQ video delivery, etc. Most practical intra coding systems employ JPEG encoders due to their simplicity, low coding delay and low memory requirement...
Article
Full-text available
It is well known that PSNR does not always rank quality of an image or video sequence in the same way that a human being. There are many other factors considered by the human visual system and the brain. So, a lot of efforts were required to find an objective video quality metric that is able to measure the quality distortion similarly to the one p...
Article
Multipath routing protocols have proved to be able to enhance the performance of MANET in terms of reliability, load balancing, multimedia streaming, security, etc. However, deploying a QoS framework on top of such routing protocols is a complex task, requiring an appropriate QoS strategy to be developed and deployed. In this paper we propose an ad...
Article
Full-text available
In this paper, a new image compression algorithm is proposed based on the efficient construction of wavelet coefficient lower trees. The main contribution of the proposed lower-tree wavelet (LTW) encoder is the utilization of coefficient trees, not only as an efficient method of grouping coefficients, but also as a fast way of coding them. Thus, it...
Conference Paper
Full-text available
For a lossy encoder, it is important to be able to provide also lossless compression with little or no modification of the usual algorithm, so that an implementation of that algorithm can work in lossy or lossless mode, depending on the specific application, simply by varying the input parameters. In this paper, we evaluate the capability of the Lo...
Conference Paper
Full-text available
When comparing the performance of different video coding approaches, improvements or new codec designs, one of the most important performance metrics is the rate/distortion (R/D), where distortion use to be measured in terms of PSNR (peak signal-to-noise ratio) values. However, it is well known that this metric not always capture the distortion per...
Article
Full-text available
In this paper, we present a new wavelet image encoder that focuses on overcoming the main drawbacks of other wavelet based-image coders; their high memory requirements and complexity. In our proposal, we tackle these problems in both parts of the wavelet coder, both the DWT algorithm and the coding system. For the DWT, we propose the use of a lineb...
Conference Paper
Full-text available
A new image coder is described in this paper. Since it is based on the Discrete Wavelet Transform (DWT), it yields good Rate/Distortion (R/D) performance. However, our proposal focuses on overcoming the two main problems of wavelet-based image coders: they are typically implemented by memory-intensive and time-consuming algorithms. In order to avoi...
Conference Paper
Full-text available
A wide variety of wavelet-based image compression schemes have been reported in the literature. Every new encoder introduces different techniques that can be taken into account for designing a new image encoder. In this paper, we present several design options and optimizations that will be used along with the LTW algorithm. However, these optimiz...
Article
Full-text available
Multimedia network systems require image and video compression schemes in order to efficiently take profit from the available bandwidth. In this paper, we present a wavelet still-image coder, called LTW (Lower-Tree Wavelet), based on the construction and codification of coefficient trees as other proposals do. This algorithm is fast and symmetric (...
Conference Paper
Full-text available
During the last decade, a lot of research and development efforts have been made to design competitive still image coders for several kinds of applications. We present a new wavelet still-image coder, called LTW (lower-tree wavelet), based on the construction and codification of coefficient trees, as other proposals are. This algorithm is fast and...
Article
Full-text available
IntroductIon Underwater sound has probably been used by marine speci-mens for millions of years as a communication capability among the members of a same species. It is said that in 1490, Leonardo Da Vinci wrote the following sentence: "If you cause your ship to stop and place the head of a long tube in the water and place the outer extremity to yo...
Article
Full-text available
Intra video coding is a common way to process video material for applications like professional video editing systems, digital cinema, video surveillance applications, multispectral satellite imaging, HQ video delivery, etc. So, a fast access to video content and the high quality reconstructed video are primary concerns. Most practical intra coding...

Projects

Projects (2)