Eduardo Quevedo

Super-resolution with adaptive macro-block topology applied to a multi-camera system

Super-Resolution (SR) consists in processing an image or a set of images in order to enhance the resolution of a video sequence or a single frame. In this paper, fusion SR techniques are considered, where High-Resolution (HR) images are constructed from several observed Low-Resolution (LR) images, thereby increasing the high-frequency components and removing the degradations caused by the recording process of LR imaging acquisition devices. This paper follows a strategy combining the selection of the most appropriate frames and adaptive sized Macro-Blocks (MBs) together with a Multi-Camera (MC) system. This proposal optimizes the spatial and temporal correlations between the recorded sequences, and minimizes the appearance of annoying artifacts at the same time, improving the quality of the super-resolved HR sequence and reducing the computational cost by more than a factor of two. This type of image enhancement systems has many applications in Consumer Electronics appliances related to imaging. More specifically, many camera suppliers are incorporating Super-Resolution in their high-end products.

A mathematical proof of how fast the diameters of a triangle mesh tend to zero after repeated trisection

The Longest-Edge (LE) trisection of a triangle is obtained by joining the two points which divide the longest edge in three with the opposite vertex. If LE-trisection is iteratively applied to an initial triangle, then the maximum diameter of the resulting triangles is between two sharpened decreasing functions. This paper mathematically answers the question of how fast the diameters of a triangle mesh tend to zero as repeated trisection is performed, and completes the previous empirical studies presented in the MASCOT 2010 Meeting (Perdomo et al., 2010).

A Hybrid Cloud Computing Approach for Intelligent Processing and Storage of Scientific Data

This paper covers a new approach on Cloud Computing for Scientific Data Storage and Processing using a hybrid system with both on-site and on-the-cloud systems. The system analyzes use cases which are not resolved by either one of the single systems themselves.

Underwater Electromagnetic Sensor Networks—Part I: Link Characterization

Underwater Wireless Sensor Networks (UWSNs) using electromagnetic (EM) technology in marine shallow waters are examined, not just for environmental monitoring but for further interesting applications. Particularly, the use of EM waves is reconsidered in shallow waters due to the benefits offered in this context, where acoustic and optical technologies have serious disadvantages. Sea water scenario is a harsh environment for radiocommunications, and there is no standard model for the underwater EM channel. The high conductivity of sea water, the effect of seabed and the surface make the behaviour of the channel hard to predict. This justifies the need of link characterization as the first step to approach the development of EM underwater sensor networks. To obtain a reliable link model, measurements and simulations are required. The measuring setup for this purpose is explained and described, as well as the procedures used. Several antennas have been designed and tested in low frequency bands. Agreement between attenuation measurements and simulations at different distances was analysed and made possible the validation of simulation setups and the design of different communications layers of the system. This leads to the second step of this work, where data and routing protocols for the sensor network are examined.

Underwater Electromagnetic Sensor Networks, Part II: Localization and Network Simulations

In the first part of the paper, we modeled and characterized the underwater radio channel in shallow waters. In the second part, we analyze the application requirements for an underwater wireless sensor network (U-WSN) operating in the same environment and perform detailed simulations. We consider two localization applications, namely self-localization and navigation aid, and propose algorithms that work well under the specific constraints associated with U-WSN, namely low connectivity, low data rates and high packet loss probability. We propose an algorithm where the sensor nodes collaboratively estimate their unknown positions in the network using a low number of anchor nodes and distance measurements from the underwater channel. Once the network has been self-located, we consider a node estimating its position for underwater navigation communicating with neighboring nodes. We also propose a communication system and simulate the whole electromagnetic U-WSN in the Castalia simulator to evaluate the network performance, including propagation impairments (e.g., noise, interference), radio parameters (e.g., modulation scheme, bandwidth, transmit power), hardware limitations (e.g., clock drift, transmission buffer) and complete MAC and routing protocols. We also explain the changes that have to be done to Castalia in order to perform the simulations. In addition, we propose a parametric model of the communication channel that matches well with the results from the first part of this paper. Finally, we provide simulation results for some illustrative scenarios.

Spatial-temporal video enhancement using super-resolution from a multi-camera system

Super-Resolution (SR) covers a set of techniques which objective is to improve the resolution of a video sequence or a single frame. In this scope, a fusion SR algorithm has been used, where High-Resolution (HR) images are constructed from several observed Low-Resolution (LR) images. In this paper, this approach is combined with a Multi-Camera (MC) system to take advantage at the same time from the spatial and temporal correlations between the recorded sequences, in order to improve the quality of the super-resolved HR sequence.

Web Georeferenced Video Player with Super-Resolution Screenshot Feature

In order to play georeferenced videos, The Oceanic Platform of the Canary Islands (PLOCAN) is currently using a desktop-based software. In this paper, a port to a web-based video player is reviewed. In addition to its main advantages, new features are also discussed, such as the download of super-resolved frames.

Improving underwater video navigation systems using Georeferencing and Super-Resolution techniques

Georeferencing consists in establishing a relationship between information and geographic locations, usually through geospatial referencing (i.e., longitude and latitude coordinates). Super-Resolution is a technique that enhances the spatial resolution of an imaging system. In this paper, the integration of both Georeferencing and Super-Resolution techniques is presented for video navigation in the web landscape applied to underwater videos.

Approach to Super-Resolution Through the Concept of Multicamera Imaging

Super-resolution consists of processing an image or a set of images in order to enhance the resolution of a video sequence or a single frame. There are several methods to apply super-resolution, from which fusion super-resolution techniques are considered to be the most adequate for real-time implementations. In fusion, super-resolution and highresolution images are constructed from several observed low-resolution images, thereby increasing the high-frequency components and removing the degradations caused by the recording process of low-resolution imaging acquisition devices. Moreover, the proposed imaging system considered in this work is based on capturing various frames from several sensors, which are attached to one another by a P × Q array. This framework is known as a multicamera system. This chapter summarizes the research conducted to apply fusion super-resolution techniques to select the most adequate frames and macroblocks together with a multicamera array. This approach optimizes the temporal and spatial correlations in the frames and reduces as a consequence the appearance of annoying artifacts, enhancing the quality of the processed high-resolution sequence and minimizing the execution time.

Variable Size Block-Matching Super-Resolution applied to a Multi-Camera system

Variable Size Block-Matching Super-Resolution covers a set of techniques which objective is to improve the resolution of a video sequence or a single frame considering variable sized Macro-Blocks. In this paper, this approach is combined with a Multi-Camera system to take advantage from the spatial and temporal correlations between frames.