Search results for "racking"
showing 10 items of 815 documents
Registration of 3D and Multispectral Data for the Study of Cultural Heritage Surfaces
2013
International audience; We present a technique for the multi-sensor registration of featureless datasets based on the photogrammetric tracking of the acquisition systems in use. This method is developed for the in situ study of cultural heritage objects and is tested by digitizing a small canvas successively with a 3D digitization system and a multispectral camera while simultaneously tracking the acquisition systems with four cameras and using a cubic target frame with a side length of 500 mm. The achieved tracking accuracy is better than 0.03 mm spatially and 0.150 mrad angularly. This allows us to seamlessly register the 3D acquisitions and to project the multispectral acquisitions on th…
Tracking in Presence of Total Occlusion and Size Variation using Mean Shift and Kalman Filter
2011
International audience; The classical mean shift algorithm for tracking in perfectly arranged conditions constitutes a good object tracking method. However, in the real environment it presents some limitations, especially under the presence of noise, objects with varying size, or occlusions. In order to deal with these problems, this paper proposes a reliable object tracking algorithm using mean shift and the Kalman filter, which was added to the traditional algorithm as a predictor when no reliable model of the object being tracked is found. Experimental work demonstrates that the proposed mean shift Kalman filter algorithm improves the tracking performance of the classical algorithms in c…
Hand Gestures Recognition and Tracking
2013
In this project we develop a system that uses low cost web cameras to recognise gestures and track 2D orientations of the hand. This report is organized as such. First in section 2 we introduce various methods we undertook for hand detection. This is the most important step in hand gesture recognition. Results of various skin detection algorithms are discussed in length. This is followed by region extraction step (section 3). In this section approaches like contours and convex hull to extract region of interest which is hand are discussed. In section 4 a method is describe to recognize the open hand gesture. Two additional gestures of palm and fist are implemented using Haar-like features. …
Using Visual Saliency for Object Tracking with Particle Filters
2010
International audience; This paper presents a robust tracking method based on the integration of visual saliency information into the particle filter framework. While particle filter has been successfully used for tracking non-rigid objects, it shows poor performances in the presence of large illumination variation, occlusions and when the target object and background have similar color distributions. We show that considering saliency information significantly improves the performance of particle filter based tracking. In particular, the proposed method is robust against occlusion and large illumination variation while requiring a reduced number of particles. Experimental results demonstrate th…
Towards visual urban scene understanding for autonomous vehicle path tracking using GPS positioning data.
2019
This PhD thesis focuses on developing a path tracking approach based on visual perception and localization in urban environments. The proposed approach comprises two systems. The first one concerns environment perception. This task is carried out using deep learning techniques to automatically extract 2D visual features and use them to learn in order to distinguish the different objects in the driving scenarios. Three deep learning techniques are adopted: semantic segmentation to assign each image pixel to a class, instance segmentation to identify separated instances of the same class and, image classification to further recognize the specific labels of the instances. Here our system segme…
ENGAGED: System design of direct seedings under permanent cover crop without glyphosate
2022
Direct seeding under permanent cover crop (SDCV) corresponds to sow a crop in a multiyear vegetal cover crop(often clover) without soil perturbation. It is an emblematic technique of Conservation Agriculture whose agronomicand environmental interests are multiple because of the special attention paid to soils. However, the issue of weedcontrol and permanent cover crop control is central to SDCV culture systems. The use of non-selective herbicide suchas glyphosate is the most common technical lever for weed and cover crop management. Glyphosate is in the hotseat since the President of France announced its banning from 2023. It becomes necessary to find alternatives for thesustainability of t…
Analogical reasoning and its development : role of executive functions and the goal of the task
2013
This manuscript develops an issue related to the involvement of goal management capabilities and executive functions in this type of reasoning and its development. The first three experiments examine this issue in two tasks of analogical reasoning, the scene analogy task and the A:B::C:? task, through the study of visual strategies used by adults, and children aged 6-to-7. The results show differences in visual patterns related to goals, and to the inhibition of irrelevant information for the solution of the problems, between the different tasks, and between children and adults. The following two experiments study the visual strategies, always in relation to executive functioning and goal m…
Comprehension of complex animation : cueing, segmentation and 2D / 3D presentations
2011
The goal of our studies was to test the effect of segmentation, cueing, and 2D/3D presentations to foster complex animation rocessing. The material was an upright mechanical piano system. We used an eye tracking system which provides information about learners’ attention direction during the animation processing. We analyzed the effect of the format presentations and the eye movements during learning. Based on animation and multimedia research background, four experiments were conducted. In the first experiment the effect of the presentation of simplified external representations on learning from complex animation was investigated. Experiment two and three aimed at studying the cognitive pr…
Comparing competing views of analogy making using eye-tracking technology
2016
International audience; We used eye-tracking to study the time course of analogical reasoning in adults. We considered proportions of looking times and saccades. The main question was whether or not adults would follow the same search strategies for different types of analogical problems (Scene Analogies vs. Classical A:B:C:D vs a Scene version of A:B::C:D). We then compared these results to the predictions of various models of analogical reasoning. Results revealed a picture of common search patterns with local adaptations to the specifics of each paradigm in both looking-time duration and the number and types of saccades. These results are discussed in terms of conceptions of analogical r…
Apprentissage implicite de régularités : Mise en évidence d'une différence d'apprentissage entre tâches motrices continues et discrètes
2005
This research is concerned with the implicit learning of regularities in continuous motor tasks (e.g., tracking tasks) and discrete tasks (e.g., Serial Reaction Time tasks). First, a reanalysis of Wulf and collaborator's studies, dealing with implicit motor learning, made it possible to highlight methodological problems and potential biases that provide alternative explanations for the apparent implicit learning obtained in their continuous tracking experiments. Indeed, by respecting a more rigorous methodology, it appears that it is quite difficult to obtain such learning in a continuous task. This led us to try to understand why it was easier to draw benefit from a repetition in a discret…