Intelligent video surveillance systems detect pre-configured surveillance events through background modeling, foreground and object extraction, object tracking, and event detection. Shadow regions inside video frames sometimes appear as foreground objects, interfere with ensuing processes, and finally degrade the event detection performance of the systems. Conventional studies have mostly used intensity, color, texture, and geometric information to perform shadow detection in daytime video, but these methods lack the capability of removing shadows in nighttime video. In this paper, a novel shadow detection algorithm for nighttime video is proposed; this algorithm partitions each foreground object based on the object's vertical histogram and screens out shadow objects by validating their orientations heading toward regions of light sources. From the experimental results, it can be seen that the proposed algorithm shows more than 93.8% shadow removal and 89.9% object extraction rates for nighttime video sequences, and the algorithm outperforms conventional shadow removal algorithms designed for daytime videos.
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http://dx.doi.org/10.3390/s17030659 | DOI Listing |
J Pediatr
January 2025
Nanit Research Department, New York, New York.
Objective: To examine prospectively the relationship between teething and infant sleep using objective sleep measurements.
Study Design: Over a 4-week period, 849 infants aged 3-18 months (mean = 8.4 ± 1.
Glob Chang Biol
December 2024
School of Biological Sciences, University of Bristol, Bristol, UK.
Artificial light at night (ALAN) is an anthropogenic pollutant that is intensifying and expanding in marine environments, but experimental studies of community-level effects are generally lacking. The inshore, shallow, and clear-water locations of coral reefs and their diverse photosensitive inhabitants make these ecosystems highly susceptible to biological disturbances; at the same time, their biodiversity and accessibility make them model systems for wider insight. Here, we experimentally manipulated ALAN using underwater LED lights on a Polynesian reef system to investigate the influence on localised nighttime fish communities compared to control sites without ALAN.
View Article and Find Full Text PDFJMIR Public Health Surveill
December 2024
Manchester Centre for Health Psychology, Division of Psychology and Mental Health, The University of Manchester, Manchester, United Kingdom.
Background: Unobtrusive observation is a promising method for assessing physical activity and other well-being behaviors (eg, social interactions) in urban environments, without participant burden and biases associated with self-report. However, current methods require multiple in-person observers. Using video cameras instead could allow for more accurate observations at lower cost and with greater flexibility in scheduling.
View Article and Find Full Text PDFAust Crit Care
December 2024
Department of Intensive Care, Fiona Stanley Hospital, Perth, Western Australia, Australia; School of Medicine, University of Western Australia, Perth, Western Australia, Australia.
Front Plant Sci
October 2024
College of Engineering, South China Agricultural University, Guangzhou, China.
Introduction: Studying the behavioral responses and movement trajectories of insects under different stimuli is crucial for developing more effective biological control measures. Therefore, accurately obtaining the movement trajectories and behavioral parameters of insects in three-dimensional space is essential.
Methods: This study used the litchi pest as the research object.
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