Miguel Onofre Martínez-Rach

Universidad Miguel Hernández de Elche | UMH · Computer Engigeering

Video streaming over VANETs is a very challenging task due both to the network characteristics (packet-loss-prone networks), and to the video streaming requirements (high bandwidth), and so, solutions need to be provided in order to keep the received video over a minimum quality threshold. The specific case of use studied applies video streaming ov...

It is well-known that each new video coding standard significantly increases in computational complexity with respect to previous standards, and this is particularly true for the HEVC and VVC video coding standards. The development of techniques for reducing the required complexity without affecting the rate/distortion (R/D) performance is therefor...

The proportion of video traffic on the internet is expected to reach 82% by 2022, mainly due to the increasing number of consumers and the emergence of new video formats with more demanding features (depth, resolution, multiview, 360, etc.). Efforts are therefore being made to constantly improve video compression standards to minimize the necessary...

The audiovisual entertainment industry has entered a race to find the video encoder offering the best Rate/Distortion (R/D) performance for high-quality high-definition video content. The challenge consists in providing a moderate to low computational/hardware complexity encoder able to run Ultra High-Definition (UHD) video formats of different fla...

Each new video encoding standard includes encoding techniques that aim to improve the performance and quality of the previous standards. During the development of these techniques, PSNR was used as the main distortion metric. However, the PSNR metric does not consider the subjectivity of the human visual system, so that the performance of some codi...

Traditionally, it has been assumed that the compression of the sign of wavelet coefficients is not worth the effort because they form a zero-mean process. However, several image encoders such as JPEG 2000 include sign-coding capabilities. In this paper, we analyze the convenience of including sign-coding techniques into wavelet-based image encoders...

In this paper, we present the methodology developed in a course of Artificial Intelligence and Pattern Recognition. The methodology is focused on building a face recognition system. For this purpose, we developed an own face recognition database named “Medfaces”. This database contains controlled and wild images for the same subjects, and it also c...

En este artículo se han analizado dos técnicas de codificación perceptual, como son texture masking y contrast masking, aplicadas al estándar de codificación de vídeo HEVC. Para el texture masking se han adaptado algoritmos utilizados en compresión de imágenes a las características del HEVC, como es su transformada y los diferentes tamaños de bloqu...

Se ha diseñado un emulador HEVC Intra en Matlab con el objetivo de proporcionar a la comunidad científica y educativa una herramienta que implementa las diferentes etapas de codificación Intra del estándar HEVC y obtiene resultados mediante curvas rate-distortion y valores BD-Rate para distintas métricas objetivas de calidad. Las etapas de transfor...

In 2016, 73% of total Internet traffic came from video transmission and this percentage is expected to reach 82% by 2021. These figures show the importance of using video compression standards that maximize video quality while minimizing the necessary bandwidth. In 2013, the HEVC standard was released accounting for an approximate 50% bit rate savi...

Nowadays, more and more vehicles are equipped with communication capabilities, not only providing connectivity with onboard devices, but also with off-board communication infrastructures. From road safety (i.e., multimedia e-call) to infotainment (i.e., video on demand services), there are a lot of applications and services that may be deployed in...

Uniform quantization schemas with dead zone are widely used in image and video codecs. The design of these quantizers affects to the final R/D performance, being two of the quantizer parameters the responsible for that variations: the dead zone size and the reconstruction point location inside each quantization step. In this work we tune the quanti...

Given the large growth in the number of smartphone users worldwide and the need to create apps for these devices, app programming for smartphones and tablets has become an important ability to any engineering student. Thus, in this article we present the educational activities carried out to ensure all engineering students have basic knowledge abou...

This work presents our experience on Android teaching at Miguel Hernández University (Elche, Spain). We decided to orientate our courses toward Android app development, and encouraged students to carry their Android phones or tablets to the classroom. The results, in terms of student motivation, satisfaction and engagement in programming have been...

With future vehicles equipped with processing capability, storage, and communications, vehicular networks will become a reality. A vast number of applications will arise that will make use of this connectivity. Some of them will be based on video streaming. In this paper we focus on HEVC video coding standard streaming in vehicular networks and how...

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...

Video delivery over VANETs is a difficult task. On the one hand, video streaming is a demanding application, where big deals of data need to be processed and transmitted. On the other hand, VANETs are error prone networks due to the high mobility of the nodes and the wireless channel. The sum of these two factors makes video transmission a hard to...

Discrete Wavelet Transform has proved to be powerful for image compression because it is able to compact frequency and spatial localization of image energy into a small fraction of coefficients. For a long time it was assumed that there is no compression gain when coding the sign of wavelet coefficients. However, several attempts were carried out a...

Depth Image Base Rendering (DIBR) is an effective approach for 3D-TV, however quality and time consistence of the depth map is a problem in this field. Our intermediate solution between Intra and Inter encoders is able to cope with the quality and time consistency of the captured depth map info. Our encoder achieves the same visual quality than H26...

This paper presents a perceptually enhanced intra-mode video encoder based on the Contrast Sensitivity Function (CSF) with a gracefully quality degradation as compression rate increases. The proposed encoder is highly competitive especially for high definition video formats at high video quality applications with constrained real-time and power pro...

When optimizing a wavelet image coder, the two main targets are to (1) improve its rate-distortion (R/D) performance and (2) reduce the coding times. In general, the encoding engine is mainly responsible for achieving R/D performance. It is usually more complex than the decoding part. A large number of works about R/D or complexity optimizations ca...

During the last two decades Red Palm Weevil (RPW, Rynchophorus Ferrugineus) has become one of the most dangerous threats to palm trees in many parts of the World. Its early detection is difficult, since palm trees do not show visual evidence of infection until it is too late for them to recover. For this reason the development of efficient early de...

Monitoring pest insect populations is currently a key issue in agriculture and forestry protection. At the farm level, human operators typically must perform periodical surveys of the traps disseminated through the field. This is a labor-, time- and cost-consuming activity, in particular for large plantations or large forestry areas, so it would be...

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...

During the last decade, there has been an increasing interest in the design of very fast wavelet image encoders focused on specific applications like interactive real-time image and video systems, running on power-constrained devices such as digital cameras, mobile phones where coding delay and/or available computing resources (working memory and p...

In this paper, the sensitivity of the HVS towards binocular disparity depth cue, which is the most important cue in modern stereoscopic 3D displays, is investigated under different ambient illumination conditions. The experimental results indicate that as ambient illumination increases the sensitivity of the HVS for depth details increases or the J...

Depth maps, which aid the virtual view generation process in Depth Image Based Rendering (DIBR) applications in 3D video, are generally piecewise smooth images with sharp depth discontinuities. Compression artifacts that occur along the depth discontinuities often lead to poor quality of generated virtual views. In line with the importance of depth...

3D-DWT encoders are good candidates for applications like professional video editing, IPTV video surveillance, live event IPTV broadcast, multispectral satellite imaging, HQ video delivery, etc., where a frame must be reconstructed as fast as possible. However, the main drawback of the algorithms that compute the 3D-DWT is the huge memory requireme...

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...

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...

In this chapter we have analyzed the performance of current commercial video codecs for video streaming through 802.11 networks running in a remotely teleoperated mobile robots testbed. We have developed a client-server application based in DirectX/DirectShow architecture for testing video compression, data delivery and error resilience behavior in...

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...

Resumen— PSNR does not always rank quality of an image or video sequence in the same way that a human being. When evaluating coding proposals under spe-cific distortion like compression or packet losses, the use of the PSNR as quality assessment metric does not guaranty the correct interpretation of the perfor-mance of the proposed encoders measure...

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...

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...

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...

The 3D-DWT is a mathematical tool of increasing importance. 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 frame-by-frame algorithm to calculate the 3D-DWT with low memory usage. This algorithm is general, in the sense that it can be emp...

Delivery of video encoded bitstreams in wireless networks is a challenging task due to different factors (node mobility, time-varying wireless channel, etc.) that put in evidence the lack of QoS support for this kind of applications. In particular, we are working with teleoperated mobile robot systems. Our purpose is to perform a study about the be...

Recently, there has been an increasing interest in the design of very fast wavelet image encoders focused on applications (interactive real-time image&video applications, GIS systems, etc) and devices (digital cameras, mobile phones, PDAs, etc) where coding delay and/or available computing resources (working memory and power processing) are critica...

Most recently developed wavelet image emcoders support as native feature an embedded bitrate control that could be useful for applications where obtaining an accurate bitrate is critical. Well-known encoders like JPEG2000 and SPIHT employ embedded coding. However, this feature makes them highly complex, being a serious restriction for certain appli...

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...

Resumen Se exponen las experiencias y resultados obtenidos en el desarrollo de las prácticas de asignaturas relativas a tecnologías de la información. Debido a la evolución tecnológica en los terminales y servicios de la telefonía móvil, se ha pretendido innovar en las prácticas de las asignaturas de las titulaciones de Ingeniero Técnico en Informá...

One of the most important performance metrics for evaluation and comparison of image or video codecs is the Rate/Distortion (R/D) where quality is measured in terms of PSNR (Peak Signal-to- Noise Ratio). 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 fac...

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...

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...

Most wavelet based encoders, do not compress the wavelet coefficients sign because it has been as-sumed to be inefficient for a long time. However, in the last years several image encoders like JPEG 2000 include sign coding capabilities. In this pa-per, we present a new sign coding approximation which uses a genetic algorithm to efficiently predict...

Resumen En este artículo se pretende recoger la experiencia realizada en la asignatura 'Sistemas Operativos' de segundo curso de Ingeniería Técnica en Informática de Gestión, impartida en la Escuela Politécnica Superior de Orihuela de la Universidad Miguel Hernández. En concreto la experiencia se ha realizado sobre la parte del temario de la asigna...