Active Vision Research Articles

Postural correlates of pleasant landscapes visual perception

IntroductionThe interplay between motor skills and emotions in the brain represents a significant and longstanding research question. Recently, posturography has provided new insights into this subject. Understanding the biological processes that influence the appreciation of nature and landscapes is also a crucial concern, prompting various experimental methods and theoretical frameworks. This research aimed to propose, for the first time, the use of posturography to study the different ways postural control is modulated by visual perception of pleasant scenes.MethodsA total of 37 participants (27 females, 10 males; mean age = 24 years ±5 years) were shown images of pleasant and neutral landscapes, while posturographic data were collected. Two viewing conditions were employed: passive vision and active vision, where participants were instructed to envision themselves in the presented scenes.ResultsThe results indicated a differential modulation of the postural response based on valence factors (pleasant vs. neutral) and mental simulation (passive vs. active). Notably, significant differences in approach-avoidance behavior were observed approximately 7 s after the onset of stimulus viewing.DiscussionThe findings are discussed in relation to major theories in environmental psychology, highlighting the central role of emotional and embodiment processes in appreciating pleasant environmental scenes and related motor behaviors.

The relationship between vision status and its influencing factors among primary and secondary school students: The masking effect of physical activity level and the moderating effect of academic stress

BackgroundThe global youth myopia rate continues to rise, and the vision health of primary and secondary school students has become a global concern. This cross-sectional study aims to explore the vision status of primary and secondary school students in the Ningxia Hui Autonomous Region, China, and its internal relationship with influencing factors under regional characteristics.MethodsA survey was conducted among 1,670 primary and secondary school students in the Ningxia Hui Autonomous Region of China using a snapshot method and random sampling techniques from September to October 2023. The survey instruments included vision examination, the International Physical Activity Questionnaire, the Lifestyle Behavior Scale, and the Student Academic Stress Questionnaire. The data was tested with descriptive statistics, difference test, correlation analyses, regression analyses, and so on using SPSS 25.0 and SPSSAU, and the target model was established and tested for the goodness-of-fit with AMOS 23.0.ResultsThere was a significant negative correlation between vision status and lifestyle behaviors (r=-0.360, p < 0.01), physical activity level (r=-0.058, p < 0.05). The physical activity level played a significant masking effect between lifestyle behaviors and vision status (a*b = 0.002, c’=-0.044), and academic stress played a moderating role in the process of lifestyle behaviors affecting physical activity level and vision status. A moderated mediator model was constructed and fitted well (RMSEA = 0.028, CFI = 0.953, NFI = 0.934).ConclusionsThe prevalence rate of myopia among primary and secondary school students in Ningxia Hui Autonomous Region is lower than the national average, and its prevalence is related to lifestyle behaviors, physical activity level, and academic stress. The impact of lifestyle behaviors on vision status is controlled by physical activity level and academic stress. A strategy of coordinated education involving families, schools, and communities should be implemented. Parents should avoid having excessive expectations and additional academic burdens on their children and encourage them to actively participate in sports; schools should fully implement the ‘’Double Reduction’’ policy, making myopia prevention and control an important part of health education; communities should carry out publicity work for myopia prevention and control, raising adolescents’ awareness of eye health.

Active vision in freely moving marmosets using head-mounted eye tracking.

Our understanding of how vision functions as primates actively navigate the real-world is remarkably sparse. As most data have been limited to chaired and typically head-restrained animals, the synergistic interactions of different motor actions/plans inherent to active sensing-e.g., eyes, head, posture, movement, etc.-on visual perception are largely unknown. To address this considerable gap in knowledge, we developed an innovative wireless head-mounted eye-tracking system that performs Chair-free Eye-Recording using Backpack mounted micROcontrollers (CEREBRO) for small mammals, such as marmoset monkeys. Because eye illumination and environment lighting change continuously in natural contexts, we developed a segmentation artificial neural network to perform robust pupil tracking in these conditions. Leveraging this innovative system to investigate active vision, we demonstrate that although freely moving marmosets exhibit frequent compensatory eye movements equivalent to other primates, including humans, the predictability of the visual behavior (gaze) is higher when animals are freely moving relative to when they are head-fixed. Moreover, despite increases in eye/head-motion during locomotion, gaze stabilization remains steady because of an increase in vestibularocular reflex gain during locomotion. These results demonstrate the efficient, dynamic visuo-motor mechanisms and related behaviors that enable stable, high-resolution foveal vision in primates as they explore the natural world.

IEEE CIS VP-Member Activities Vision Statement [Society Briefs

IEEE CIS VP-Member Activities Vision Statement [Society Briefs

The representation of stimulus features during stable fixation and active vision.

Predictive updating of an object's spatial coordinates from pre-saccade to post-saccade contributes to stable visual perception. Whether object features are predictively remapped remains contested. We set out to characterise the spatiotemporal dynamics of feature processing during stable fixation and active vision. To do so, we applied multivariate decoding methods to electroencephalography (EEG) data collected while human participants (male and female) viewed brief visual stimuli. Stimuli appeared at different locations across the visual field at either high or low spatial frequency (SF). During fixation, classifiers were trained to decode SF presented at one parafoveal location and cross-tested on SF from either the same, adjacent or more peripheral locations. When training and testing on the same location, SF was classified shortly after stimulus onset (∼79 ms). Decoding of SF at locations farther from the trained location emerged later (∼144 - 295 ms), with decoding latency modulated by eccentricity. This analysis provides a detailed time course for the spread of feature information across the visual field. Next, we investigated how active vision impacts the emergence of SF information. In the presence of a saccade, the decoding time of peripheral SF at parafoveal locations was earlier, indicating predictive anticipation of SF due to the saccade. Crucially however, this predictive effect was not limited to the specific remapped location. Rather, peripheral SF was correctly classified, at an accelerated time course, at all parafoveal positions. This indicates spatially coarse, predictive anticipation of stimulus features during active vision, likely enabling a smooth transition on saccade landing.Significance Statement Maintaining a continuous representation of object features across saccades is vital for stable vision. In order to characterise the spatiotemporal dynamics of stimulus feature representation in the brain, we presented stimuli at a high and low spatial frequency at multiple locations across the visual field. Applying EEG-decoding methods we tracked the neural representation of spatial frequency during both stable fixation and active vision. Using this approach, we provide a detailed time course for the spread of feature information across the visual field during fixation. In addition, when a saccade is imminent, we show that peripheral spatial frequency is predictively represented in anticipation of the post-saccadic input.

Memory-based predictions prime perceptual judgments across head turns in immersive, real-world scenes.

Each view of our environment captures only a subset of our immersive surroundings. Yet, our visual experience feels seamless. A puzzle for human neuroscience is to determine what cognitive mechanisms enable us to overcome our limited field of view and efficiently anticipate new views as we sample our visual surroundings. Here, we tested whether memory-based predictions of upcoming scene views facilitate efficient perceptual judgments across head turns. We tested this hypothesis using immersive, head-mounted virtual reality (VR). After learning a set of immersive real-world environments, participants (n = 101 across 4 experiments) were briefly primed with a single view from a studied environment and then turned left or right to make a perceptual judgment about an adjacent scene view. We found that participants' perceptual judgments were faster when they were primed with images from the same (vs. neutral or different) environments. Importantly, priming required memory: it only occurred in learned (vs. novel) environments, where the link between adjacent scene views was known. Further, consistent with a role in supporting active vision, priming only occurred in the direction of planned head turns and only benefited judgments for scene views presented in their learned spatiotopic positions. Taken together, we propose that memory-based predictions facilitate rapid perception across large-scale visual actions, such as head and body movements, and may be critical for efficient behavior in complex immersive environments.

STATUS OF RESIDENTIAL SOLID WASTE MANAGEMENT. A CASE STUDY IN DONG ANH DISTRICT, HANOI, VIETNAM

Residential solid wastes have been becoming an environmental threat for every city, especially crown and high population. The status of Residential Solid Waste (RSW) in a large city, such as Hanoi in general and Dong Anh district in particular, can bring a better vision for management activities. In this study, RSW will be carried out to assess the sources and component contribution being inputs for further forecasting of generated RSW until 2025 in study areas, Dong Anh district, the Tien Duong, and Uy No communes. This study applies the separation of the waste in sites and surveys to calculate the Generated Residential Solid Waste Rate (GRSWR) and in combination with the increased population rate from the famous Euler’s model to predict and forecast the Generated Residential Solid Waste (GRSW) in Dong Anh in the 5 years (2020 - 2025). The results show that the increase in population for every study region will lead to an increase in RSW. In particular, the total GRSW will increase by more than 1,000 tons/year with only 1,000 raised citizens in 5 years. The overall trash collection rate reaches 86.5 % of the total waste generated in the area. The residential waste composition of the Dong Anh district is extremely diverse, with organic matter accounting for nearly 75 %, higher than the average of Hanoi. The important thing is to rigorously and thoroughly implement waste classification at the source according to the regulations of the Law on Environmental Protection (2020) to reduce the amount of waste generated that needs to be collected.

Research on UAV Autonomous Recognition and Approach Method for Linear Target Splicing Sleeves Based on Deep Learning and Active Stereo Vision

This study proposes an autonomous recognition and approach method for unmanned aerial vehicles (UAVs) targeting linear splicing sleeves. By integrating deep learning and active stereo vision, this method addresses the navigation challenges faced by UAVs during the identification, localization, and docking of splicing sleeves on overhead power transmission lines. First, a two-stage localization strategy, LC (Local Clustering)-RB (Reparameterization Block)-YOLO (You Only Look Once)v8n (OBB (Oriented Bounding Box)), is developed for linear target splicing sleeves. This strategy ensures rapid, accurate, and reliable recognition and localization while generating precise waypoints for UAV docking with splicing sleeves. Next, virtual reality technology is utilized to expand the splicing sleeve dataset, creating the DSS dataset tailored to diverse scenarios. This enhancement improves the robustness and generalization capability of the recognition model. Finally, a UAV approach splicing sleeve (UAV-ASS) visual navigation simulation platform is developed using the Robot Operating System (ROS), the PX4 open-source flight control system, and the GAZEBO 3D robotics simulator. This platform simulates the UAV’s final approach to the splicing sleeves. Experimental results demonstrate that, on the DSS dataset, the RB-YOLOv8n(OBB) model achieves a mean average precision (mAP0.5) of 96.4%, with an image inference speed of 86.41 frames per second. By incorporating the LC-based fine localization method, the five rotational bounding box parameters (x, y, w, h, and angle) of the splicing sleeve achieve a mean relative error (MRE) ranging from 3.39% to 4.21%. Additionally, the correlation coefficients (ρ) with manually annotated positions improve to 0.99, 0.99, 0.98, 0.95, and 0.98, respectively. These improvements significantly enhance the accuracy and stability of splicing sleeve localization. Moreover, the developed UAV-ASS visual navigation simulation platform effectively validates high-risk algorithms for UAV autonomous recognition and docking with splicing sleeves on power transmission lines, reducing testing costs and associated safety risks.

Biomimetic Active Stereo Camera System with Variable FOV.

Inspired by the biological eye movements of fish such as pipefish and sandlances, this paper presents a novel dynamic calibration method specifically for active stereo vision systems to address the challenges of active cameras with varying fields of view (FOVs). By integrating static calibration based on camera rotation angles with dynamic updates of extrinsic parameters, the method leverages relative pose adjustments between the rotation axis and cameras to update extrinsic parameters continuously in real-time. It facilitates epipolar rectification as the FOV changes, and enables precise disparity computation and accurate depth information acquisition. Based on the dynamic calibration method, we develop a two-DOF bionic active camera system including two cameras driven by motors to mimic the movement of biological eyes; this compact system has a large range of visual data. Experimental results show that the calibration method is effective, and achieves high accuracy in extrinsic parameter calculations during FOV adjustments.

Unsupervised Active Visual Search With Monte Carlo Planning Under Uncertain Detections.

We propose a solution for Active Visual Search of objects in an environment, whose 2D floor map is the only known information. Our solution has three key features that make it more plausible and robust to detector failures compared to state-of-the-art methods: i) it is unsupervised as it does not need any training sessions. ii) During the exploration, a probability distribution on the 2D floor map is updated according to an intuitive mechanism, while an improved belief update increases the effectiveness of the agent's exploration. iii) We incorporate the awareness that an object detector may fail into the aforementioned probability modelling by exploiting the success statistics of a specific detector. Our solution is dubbed POMP-BE-PD (Pomcp-based Online Motion Planning with Belief by Exploration and Probabilistic Detection). It uses the current pose of an agent and an RGB-D observation to learn an optimal search policy, exploiting a POMDP solved by a Monte-Carlo planning approach. On the Active Vision Dataset Benchmark, we increase the average success rate over all the environments by a significant 35 % while decreasing the average path length by 4 % with respect to competing methods. Thus, our results are state-of-the-art, even without any training procedure.

Dynamic calibration and multi-view fusion of active vision tracking system for surgical instrument

Abstract In recent years, surgical instrument tracking has gained significant attention in the field of surgical navigation. An often-overlooked problem lies in the instrument’s irregular movement conflicting with the tracking system’s fixed viewpoint, leading to line-of-sight (LOS) occlusion, marker occlusion, and sub-optimal accuracy. The active vision tracking system (which actively adjusts the camera viewpoint) is applied to address this issue. In this paper, two algorithms of multi-view fusion and dynamic calibration are proposed in multi-camera active vision to allow each camera to adjust its viewpoint independently. These algorithms are integrated into the parallel computing of the frontend and backend to implement the positioning of the instrument from multiple perspectives and real-time calibration of multiple cameras. Simulations and experiments are carried out to test the accuracy and robustness of the proposed tracking system. Results reveal that our system achieves a closer trajectory (0.12 mm) to the ground truth compared to a stereo camera tracking system (0.32 mm). The proposed tracking system is able to keep track of the instruments within the positioning volume at different surgical phases, ensuring consistent navigation and improving positioning stability and accuracy.&amp;#xD;

Participation of teenagers with vision or motor impairments in leisure activities: a qualitative study.

Participation in everyday life activities is important for the development of children and is an important topic in rehabilitation practices. This qualitative study aimed to unveil the perspectives and experiences of teenagers with vision impairments (VIs) or motor impairments (MIs) regarding their participation in leisure activities. 13 teenagers with VIs and 12 teenagers with MIs (age range: 11-15 years) participated in this study. Data were collected using semi-structured interviews. Verbatim transcripts were analyzed following the steps of the phenomenological approach. A total of 623 significant statements were identified and assigned to 221 meaning units. Finally, 13 themes emerged. Teenagers with VIs and MIs shared many experiences and perspectives regarding participation in leisure activities. Teenagers reported that they can sufficiently indicate what they experience as pleasant and sufficient considering their participation, as well as the challenges they encountered, such as their impairment, limited transport possibilities, or concerns from parents. Overall, teenagers with VIs or MIs were generally satisfied with the degree and frequency of their participation in leisure activities and felt sufficiently involved.

Active vision in freely moving marmosets using head-mounted eye tracking.

Our understanding of how vision functions as primates actively navigate the real-world is remarkably sparse. As most data have been limited to chaired and typically head-restrained animals, the synergistic interactions of different motor actions/plans inherent to active sensing - e.g. eyes, head, posture, movement, etc. - on visual perception are largely unknown. To address this considerable gap in knowledge, we developed an innovative wireless head-mounted eye tracking system called CEREBRO for small mammals, such as marmoset monkeys. Our system performs Chair-free Eye-Recording using Backpack mounted micROcontrollers. Because eye illumination and environment lighting change continuously in natural contexts, we developed a segmentation artificial neural network to perform robust pupil tracking in these conditions. Leveraging this innovative system to investigate active vision, we demonstrate that although freely-moving marmosets exhibit frequent compensatory eye movements equivalent to other primates, including humans, the predictability of the visual behavior (gaze) is higher when animals are freely-moving relative to when they are head-fixed. Moreover, despite increases in eye/head-motion during locomotion, gaze stabilization remains steady because of an increase in VOR gain during locomotion. These results demonstrate the efficient, dynamic visuo-motor mechanisms and related behaviors that enable stable, high-resolution foveal vision in primates as they explore the natural world.

Pixel-Level Precision Saccade Control of Arbitrary 3D Spatial Points in Active Binocular Vision Systems

Pixel-Level Precision Saccade Control of Arbitrary 3D Spatial Points in Active Binocular Vision Systems

Randomised trial of three treatments for amblyopia: Vision therapy and patching, perceptual learning and patching alone.

Active vision therapy for amblyopia shows good results, but there is no standard vision therapy protocol. This study compared the results of three treatments, two combining patching with active therapy and one with patching alone, in a sample of children with amblyopia. Two protocols have been developed: (a) perceptual learning with a computer game designed to favour the medium-to-high spatial frequency-tuned achromatic mechanisms of parvocellular origin and (b) vision therapy with a specific protocol and 2-h patching. The third treatment group used patching only. Fifty-two amblyopic children (aged 4-12 years), were randomly assigned to three monocular treatment groups: 2-h patching (n = 18), monocular perceptual learning (n = 17) and 2-h patching plus vision therapy (n = 17). Visual outcomes were analysed after 3 months and compared with a control group (n = 36) of subjects with normal vision. Visual acuity (VA) and stereoacuity (STA) improved significantly after treatment for the three groups with the best results for patching plus vision therapy, followed by monocular perceptual learning, with patching only least effective. Change in the interocular difference in VA was significant for monocular perceptual learning, followed by patching. Differences in STA between groups were not significant. For VA and interocular differences, the final outcomes were influenced by the baseline VA and interocular difference, respectively, with greater improvements in subjects with poorer initial values. Visual acuity and STA improved with the two most active treatments, that is, vision therapy followed by perceptual learning. Patching alone showed the worst outcome. These results suggest that vision therapy should include monocular accommodative exercises, ocular motility and central fixation exercises where the fovea is more active.

The relationship between visual health and influencing factors among primary and secondary school students: a survey based in the Ningxia Hui Autonomous Region of China.

The myopia rate of young people around the world, especially in China, has continued to rise, and the vision health of primary and secondary school students has gradually become a global concern. It was to explore the current characteristics of vision status and their intrinsic links to influencing factors of the Ningxia Hui Autonomous Region primary and secondary school students under regional characteristics. 1,670 primary and secondary school students in Ningxia Hui Autonomous Region were surveyed using Vision examination, International Physical Activity Scale, Lifestyle Behavior Scale. The data were analyzed using SPSS 25.0 and AMOS 23.0. The prevalence of myopia among primary and secondary school students in the Ningxia Hui Autonomous Region was 27.3%, with rates of 31.5% for girls and 23.4% for boys. There was a significant negative correlation between lifestyle behaviors (r = -0.36, p < 0.01) and physical activity level (r = -0.06, p < 0.05) with vision status. The physical activity level played a significant masking effect between lifestyle behaviors and vision status (a*b = 0.002, c' = -0.044). Gender moderated the effects of lifestyle behaviors on physical activity level and vision status, as well as the effects of physical activity level on vision status. These factors constituted a mixed model with mediating and moderation. The model fitted well (RMSEA = 0.028, CFI = 0.951, NFI = 0.918). The prevalence of myopia among primary and secondary school students in this region is lower than the national average in China, and it is associated with lifestyle behaviors, physical activity level, and gender. When effectively controlled, the physical activity level significantly will reduce the prevalence of myopia as a masking variable. Gender, as a moderating variable, provides theoretical support for the classification and prevention of myopia. Regional surveys enriched the global database on adolescent myopia research, revealing the characteristics and common factors of visual problems in adolescents. Relevant departments and schools should integrate eye care into the national health security system, implement policies related to myopia prevention and control and safeguard the visual health of primary and secondary school students.

Toward Two-Stream Foveation-Based Active Vision Learning

Toward Two-Stream Foveation-Based Active Vision Learning

Quality of Life in Patients with Birdshot Chorioretinitis Aged 80 and Older

ABSTRACT Purpose Birdshot chorioretinitis (BSCR) is an ocular HLA-related disease with variable clinical progression. We examine the quality of life (QOL) of BSCR individuals aged ≥80 years, providing insights into the long-term disease impact. Methods We utilized data from the CO-BIRD cohort (ClinicalTrials.gov Identifier: NCT05153057) conducted at Hôpital Cochin in Paris, France, focusing on BSCR patients aged ≥80. The main outcome was vision-related QOL using the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). We used Spearman correlation to explore the impact of better BCVA and MD on the composite score, and the Wilcoxon test to evaluate specific visual symptoms’ effects. Results The study included 35 patients with a mean age of 83.9 ± 3.7 years, 74.3% of whom received systemic immunosuppression. The mean composite score was 58 ± 30, with a median of 75 (23–79). The lowest subscores were driving capacity (38 ± 38), mental health (49 ± 33), and role difficulties (50 ± 35), while the highest were for ocular pain (70 ± 25) and social function (70 ± 38). Decimal BCVA below 0.5 and MD below −6 dB were associated with lower subscores. BCVA and MD were strongly correlated with the composite score (R = 0.67). Symptoms of poor color and blurry vision were significantly associated with lower composite score (p < 0.005). Conclusion Most BSCR patients over 80 in our cohort maintained sufficient vision for daily activities. The high standard deviation and wide range of VFQ-25 results reflect the heterogeneity of visual outcomes among elderly BSCR patients.

Profilometry: a non-intrusive active stereo-vision technique for wave-profile measurements in large hydrodynamic laboratories

Profilometry is proposed as a novel non-intrusive image-based technique to capture the profile of the air–water interface as a dense point cloud. It can be classified as an active stereo-vision method applied to the study of gravity-driven water waves and specifically developed to be used in large hydrodynamic laboratories. As an active vision technique, it relies on the use of light sources, and as a stereo technique, it requires one or more high-speed camera pairs for imaging the same scene synchronously. To enhance the visibility of the laser lights on the wave profile, the water surface is sprayed with water droplets. Profilometry, compared to standard wave probes, can be considered as an alternative source of information that can augment spatial resolution to the identification of the air–water interface to capture nonlinear wave-evolution mechanisms and violent wave–body interactions. Its feasibility and accuracy are examined preliminarily in a small-scale flume and then in a large-scale towing tank using long-crested wave scenarios, including regular, irregular, and focused gravity-driven waves, without the presence of a structure. The values of the wave steepness examined were various and included also quite steep cases with nearly vertical wave fronts. Role played by parameters of the technique, as well as of its setup in capturing the wave features are also analysed, with the aim to provide a useful guidance for other researchers that intent to use and develop further this approach.

Research on Camera Rotation Strategies for Active Visual Perception in the Self-Driving Vehicles

Aiming at the problem of blind field of view caused by the change in the vehicle’s yaw angle when the self-driving vehicle is turning or changing lanes, this paper proposes a camera rotation strategy based on monocular active environment sensing, which realizes the detection of the blind field of view when the vehicle’s yaw angle changes in the self-driving vehicle. Based on the two-degrees-of-freedom dynamic model, the camera rotation angle control is achieved by controlling the front-wheel angle of the vehicle. A camera control module is designed using Simulink to control the camera in real-time, allowing it to rotate based on different driving scenes. The effect of obstacle detection by traditional vision sensors and active vision sensors is tested under different vehicle driving scenes. The results demonstrate that the obstacle detection effect of the camera rotation strategy based on monocular active environment perception, as designed in this paper, is better than the traditional monocular vision.