Thi Thanh Hai - TRAN
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Temporal Gesture Segmentation | This paper presents a
method for temporal gesture segmentation based on the total activity of the
video sequence. The new point of this method is that we apply some filters on
the sequence and on the total activity plot that makes our method more robust
to noise. This method has been shown to be very efficient on a very big data of
the new contest CHALEARN on hand gesture recognition. This method can be a good
reference for participants to the CHALEARN contest. The method is generic so
could be applied for any shot boundary problem. |
Hand Posture Recognition for HRI | The use of hand gestures provides an attractive alternative to cumbersome interface devices for human - machine interaction (HMI). However, recognition of hand gestures is not a simple problem. In this paper, we propose to decompose the hand gesture recognition problem into 2 steps. In the first step, we detect skin regions using a very fast algorithm of color segmentation. In the second step, each skin region will be classified into one of hand posture class using cascaded Adaboost classifier and shape analysis techniques. The contribution of this paper is twofold. First, we proposed using both techniques for hand gesture recognition that reduces significantly the computational time in comparison with the traditional use of cascaded Adaboost classifier. Secondly, we integrated successfully this method on the robot and validated it in the context of interaction between human and robot guide in museum. |
Face Recognition | This work concerns the problem of face recognition from video under uncontrolled lighting condition. To face with illumination change, we propose to inspire the idea that pre-processes input images in order to represent them robust to illumination change [1]. We then use embedded Hidden Markov Model (EHMM), a famous model for face recognition to identify faces [2]. The main reason that we would like to study and experiment this model is that it allows us to represent structure of face images that makes more explicit face representation than numeric face descriptors. The traditional EHMM + applied to face recognition from still images. In our paper, we deal with face recognition from video. Therefore, we propose to combine the recognition result obtained from several frames to make our decision more confident. This improves significantly the recognition rate. We have trained our model and tested with two face databases, the one is the Yale-B database and the other one is created by MICA Institute. |
Ridge Extraction |
We developed a simple but efficient
algorithm to detect multiscales visual features in an image: ridges
d peaks. The method is based
on Laplacian of Gaussian of the image and differential geometry properties
of the surface associated with the image. Experiments of feature detection
carried out with many types of images (eg. CT&MR images, fingerprint images,
real-world images) showed that the method is very good for detecting
features which represent object shapes. These features enrich the set of
classical features (eg. region, contour line, interest point) and
significantly improve the representation of objects in images.
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Text Detection |
A text is a special kind of
structural object. At a small scale, we see some traits of characters. At
a larger scale, we see only a long band co rresponding to the text line.
Using these properties, we developed a method to model text in an image
using ridges. More specifically, a text is
chacharacterized by a long ridgeline at a coarse scale and several shorter
ridges perpendicular to long ridgeline at a small scale. This
reprepresentation of text is generic to many types of text: alphabet or
ideogram, scene text or artificial text and independent with text
orientation. Thedetection was evaluated on images of different nature and
gave as surprising precision and
recall (93%).
|
Hierachical Object representation |
We developed a new method for object representation based on ridges and peaks detected at several scales. Each object is represented as a graph such that each node is a feature (ridge or peak) and each arc is built from covering relation between spatial extensions of two features. T his graph describes global shape as well as details of the object and allows many efficient strategies for graph matching. |
Human Modeling |
Each person is represented by significant ridges and peaks
detected at appropriate scales, representing important human
parts like head, torso and legs. Geometrical relations between
features are explored to build a human model, which is a
vec tor of 10 components describing a
configuration of a human. This representation method was applied for
person detection in surveillance sequences. It has been evaluated on 26
video sequences provided by the CAVIAR
project and obtained a good
rate of detection (85%).
|
Tracking based on Keypoints |
We developed a real-time method for detecting keypoints in
images. These keypoints are described by a gradient
magnitude based descriptor vector, which is projected onto an
eigenspace to reduce dimensions and make faster the
search for nearest neighbors. This method has
been evaluated in the context of visual servoing: moving a robot from a
certain position to a desired position.
It worked in real-time (10-14fps) and has been shown to be very robust to
occlusion. In
addition, it is capable to reinitialize
whenever objects of interest get lost.
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People Tracking |
The project LOVe has
objectif to develop a software for vulnerable observation. This
project has 12 partners. Our laboratory at CEA takes part into this
project. We developped potential moduls: pedestrian detection from
stereo moving camera and pedestrian tracking based on
kalman filter, with help of lidar measurements.
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Image Processing | To convert an image raw into a visible image (jpeg), we have to apply an image processing process, including : Demosaicing, White Balance, Color rendering, ToneCurve. My work is specified in to developing a method for color rendering, a very important step of image processing process.s |