Search results for "pose estimation"
showing 10 items of 10 documents
SAMSLAM: Simulated Annealing Monocular SLAM
2013
This paper proposes a novel monocular SLAM approach. For a triplet of successive keyframes, the approach inteleaves the registration of the three 3D maps associated to each image pair in the triplet and the refinement of the corresponding poses, by progressively limiting the allowable reprojection error according to a simulated annealing scheme. This approach computes only local overlapping maps of almost constant size, thus avoiding problems of 3D map growth. It does not require global optimization, loop closure and back-correction of the poses.
Real-Time Human Pose Estimation from Body-Scanned Point Clouds
2015
International audience; This paper presents a novel approach to estimate the human pose from a body-scanned point cloud. To do so, a predefined skeleton model is first initialized according to both the skeleton base point and its torso limb obtained by Principal Component Analysis (PCA). Then, the body parts are iteratively clustered and the skeleton limb fitting is performed, based on Expectation Maximization (EM). The human pose is given by the location of each skeletal node in the fitted skeleton model. Experimental results show the ability of the method to estimate the human pose from multiple point cloud video sequences representing the external surface of a scanned human body; being r…
Estimating head pose and state of facial elements for sign language video
2014
In this work we present methods for automatic estimation of non-manual gestures in sign language videos. More specifically, we study the estimation of three head pose angles (yaw, pitch, roll) and the state of facial elements (eyebrow position, eye openness, and mouth state). This kind of estimation facilitates automatic annotation of sign language videos and promotes more prolific production of annotated sign language corpora. The proposed estimation methods are incorporated in our publicly available SLMotion software package for sign language video processing and analysis. Our method implements a model-based approach: for head pose we employ facial landmarks and skins masks as features, a…
FastSLAM 2.0: Least-Squares Approach
2006
In this paper, we present a set of robust and efficient algorithms with O(N) cost for the following situations: object detection with a laser ranger; mobile robot pose estimation and a FastSLAM improved implementation. Objected detection is mainly based on a novel multiple line fitting method, related with walls at the environment. This method assumes that walls at the environment constitute a regular constrained angles. A line-based pose estimation method is also proposed, based on Least-Squares (LS). This method performs the matching of detected lines and estimated map lines and it can provide the global pose estimation under assumption of known Data-Association. FastSLAM 1.0 has been imp…
Object Recognition and Modeling Using SIFT Features
2013
In this paper we present a technique for object recognition and modelling based on local image features matching. Given a complete set of views of an object the goal of our technique is the recognition of the same object in an image of a cluttered environment containing the object and an estimate of its pose. The method is based on visual modeling of objects from a multi-view representation of the object to recognize. The first step consists of creating object model, selecting a subset of the available views using SIFT descriptors to evaluate image similarity and relevance. The selected views are then assumed as the model of the object and we show that they can effectively be used to visual…
Localisation basée vision à partir de caractéristiques discriminantes issues de données visuelles hétérogènes
2019
Visual-based Localization (VBL) consists in retrieving the location of a visual image within a known space. VBL is involved in several present-day practical applications, such as indoor and outdoor navigation, 3D reconstruction, etc. The main challenge in VBL comes from the fact that the visual input to localize could have been taken at a different time than the reference database. Visual changes may occur on the observed environment during this period of time, especially for outdoor localization. Recent approaches use complementary information in order to address these visually challenging localization scenarios, like geometric information or semantic information. However geometric or sema…
Head Pose Estimation for Sign Language Video
2013
We address the problem of estimating three head pose angles in sign language video using the Pointing04 data set as training data. The proposed model employs facial landmark points and Support Vector Regression learned from the training set to identify yaw and pitch angles independently. A simple geometric approach is used for the roll angle. As a novel development, we propose to use the detected skin tone areas within the face bounding box as additional features for head pose estimation. The accuracy level of the estimators we obtain compares favorably with published results on the same data, but the smaller number of pose angles in our setup may explain some of the observed advantage.
Automatic social distance estimation for photographic studies: Performance evaluation, test benchmark, and algorithm
2022
The social distancing regulations introduced to slow down the spread of COVID-19 virus directly affect a basic form of non-verbal communication, and there may be longer term impacts on human behavior and culture that remain to be analyzed in proxemics studies. To obtain quantitative results for such studies, large media and/or personal photo collections must be analyzed. Several social distance monitoring methods have been proposed for safety purposes, but they are not directly applicable to general photo collections with large variations in the imaging setup. In such studies, the interest shifts from safety to analyzing subtle differences in social distances. Currently, there is no suitabl…
Reconstruction of urban sites from photos
2019
Abstract. This paper reports the results of an experiment that aims at the virtual reconstruction of a urban site that has been partially reshaped during the 20th century; the reconstruction process is based on period photos. The chosen case study is the eldest harbour of Palermo, named ‘Cala’; the site was bombed during World War II and new buildings took the place of the ruined ones. Two period photos, taken from an aircraft, document the buildings that were destroyed by bombs. The 3D restitution process used the ‘inverse’ projection from period photos (2D) to the virtual space (3D) ; the first step was therefore addressed to the calculation of the inner parameters (focal length, principa…
Optical measurement of virtual reality headset performance
2018
Virtuaalitodellisuussilmikoiden päänseurantajärjestelmän suorituskyvyn mittaamista varten kehitettiin mittausmenetelmä ja sulautettu kameramoduuli. Kyse on päästä päähän mittauksesta (engl. end-to-end measurement), jossa robotti liikuttaa silmikkoa ja kamera mittaa sisällön muutoksia näytöllä. Tavoitteena on optisesti mitata päänseurantajärjestelmän tarkkuutta kuvaamalla näytön sisältöä näytön virkistykseen tahdistettuna. Työssä keskityttiin kameramoduulin ja siihen liittyvien konenäköalgoritmien kehittämiseen. Mittauksessa näytöllä on kolmiulotteinen kohde, jossa on tunnistettavia pisteitä. Paikallistamalla nämä pisteet kuvassa voidaan määrittää grafiikkamoottorin virtuaalisen kameran asen…