Using pixel intensity as a self- regulating threshold for deterministic image sampling in Milano Retinex : the T-Rex algorithm

Milano Retinexes are spatial color algorithms, part of the Retinex family, usually employed for image enhancement. They modify the color of each pixel taking into account the surrounding colors and their position, catching in this way the local spatial color distribution relevant to image enhancement. We present T-Rex (from the words threshold and Retinex), an implementation of Milano Retinex, whose main novelty is the use of the pixel intensity as a self-regulating threshold to deterministically sample local color information. The experiments, carried out on real-world pictures, show that T-Rex image enhancement performance are in line with those of the Milano Retinex family: T-Rex increases the brightness, the contrast, and the flatness of the channel distributions of the input image, making more intelligible the content of pictures acquired under difficult light conditions

Analysis of Tapial structures for modern use and conservation

Tapial is an ancient form of rammed earth wall construction found in many parts of the world. In medieval Spain, Tapial was used in the construction of some large and complex structures, some many-storied. That these buildings remain standing (many remaining in use) is an indication of the durability of this form of construction, and is perhaps related to the climatic conditions found in central Spain. This paper describes an engineering study into an important structure in the Aragon region, significant parts of which are constructed in medieval Tapial, as well as other forms of construction. The aim of the study is both to improve understanding of the nature of this structure and to provide guidance on methods of preservation and new construction

Segmentation of sport videos by embedded text reading

This report presents a module for athlete recognition in broadcast videos as part of a video entertainment application. The aim is to identify athletes by means of name or number as printed on their uniform and extract the video clips where the desired athlete is visible. Using an adaptation of a previously published algorithm we extract text from each single frame and we read it by means of an optical character recognizer (OCR). The OCRed text is then compared with an a-priori known list of athletes' names or numbers to provide a score of the presence of each athlete in that frame. Presence plausibility is then checked by a temporal persistence analysis of names/numbers extracted from subsequent frames. Performed experiments show that the method is promising and can provide a useful input for a module for the identification of the athlete presence in a frame

A Computer Vision System for Traffic Accident Risk Measurement: A Case Study

Abstract - A reliable estimation of the safety level of the roads is a valuable tool for detecting critical points in the road infrastructure, planning and implement countermeasures, and evaluating their impact on the traffic. A method for the computation of the accident risk is proposed, which is based on microscopic traffic data collected automatically by a video-based monitoring system, i.e. class, speed, and tra jectory of each single road-user. The benefit of the proposed method is twofold: the risk level is computed without statistics on past accidents, and its computation is fully automated, i.e. it does not require a manual collection of traffic data. The paper presents the definition of the proposed risk index and describes its application to a real case: the evaluation of the accident risk at an urban intersection, before and after the reorganization of its geometry. The proposed risk index, although based only on those parameters that are automatically measurable, seems to reflect the expectation of traffic experts in evaluating the impact of intervention to improve the safety level of the intersection

Scene Text Recognition and Tracking to Identify Athletes in Sport Videos

We present an athlete identification module forming part of a system for the personalization of sport video broadcasts. The aim of this module is the localization of athletes in the scene, their identification through the reading of names or numbers printed on their uniforms, and the labelling of frames where athletes are visible. Building upon a previously published algorithm we extract text from individual frames and read these candidates by means of an optical character recognizer (OCR). The OCR-ed text is then compared to a known list of athletes’ names (or numbers), to provide a presence score for each athlete. Text regions are tracked in subsequent frames using a template matching technique. In this way blurred or distorted text, normally unreadable by the OCR, is exploited to provide a denser labelling of the video sequences. Extensive experiments show that themethod proposed is fast, robust and reliable, out-performing results of other systems in the literature

DIPLODOC road stereo sequence

In this note we describe a road stereo sequence acquired, stored and labelled for evaluation purposes in the DIPLODOC project. The sequence, covering different scenarios, and its ground-truth, is made freely available on the web as a common base for the evaluation of road and obstacle detection algorithms

A Smart Watch-based Gesture Recognition System for Assisting People with Visual Impairments

Modern mobile devices provide several functionalities and new ones are being added at a breakneck pace. Unfortunately browsing the menu and accessing the functions of a mobile phone is not a trivial task for visual impaired users. Low vision people typically rely on screen readers and voice commands. However, depending on the situations, screen readers are not ideal because blind people may need their hearing for safety, and automatic recognition of voice commands is challenging in noisy environments. Novel smart watches technologies provides an interesting opportunity to design new forms of user interaction with mobile phones. We present our first works towards the realization of a system, based on the combination of a mobile phone and a smart watch for gesture control, for assisting low vision people during daily life activities. More specifically we propose a novel approach for gesture recognition which is based on global alignment kernels and is shown to be effective in the challenging scenario of user independent recognition. This method is used to build a gesture-based user interaction module and is embedded into a system targeted to visually impaired which will also integrate several other modules. We present two of them: one for identifying wet floor signs, the other for automatic recognition of predefined logos

Distribuição temporal e espacial da raiva bovina em Minas Gerais, 1976 a 1997

Realizou-se um estudo observacional retrospectivo com o objetivo de avaliar a distribuição espaço-temporal da raiva bovina em Minas Gerais. Foram analisadas 7.526 fichas de diagnóstico de raiva por imunofluorescência direta, de 1976 a 1997. Para distribuição espacial da raiva bovina foi utilizado o aplicativo de mapeamento MAP-INFO Professional 4.5. Foi observada tendência crescente anual não só de diagnósticos positivos de raiva (Y=23,588X), com predominância nos meses de abril a agosto, como também de municípios positivos (Y=0,0461X), caracterizando intensa expansão da raiva bovina em Minas Gerais

Distribuição temporal e espacial da raiva bovina em Minas Gerais, 1976 a 1997

Realizou-se um estudo observacional retrospectivo com o objetivo de avaliar a distribuição espaço-temporal da raiva bovina em Minas Gerais. Foram analisadas 7.526 fichas de diagnóstico de raiva por imunofluorescência direta, de 1976 a 1997. Para distribuição espacial da raiva bovina foi utilizado o aplicativo de mapeamento MAP-INFO Professional 4.5. Foi observada tendência crescente anual não só de diagnósticos positivos de raiva (Y=23,588X), com predominância nos meses de abril a agosto, como também de municípios positivos (Y=0,0461X), caracterizando intensa expansão da raiva bovina em Minas Gerais