3D information is valuable for the detection of humans in video streams

in 3D Stereo Media (2010, December)

In this paper, we propose a technique based on 3D information (also called depth or range) for the detection of humans. First, a background subtraction technique operates to detect the silhouettes of ... [more ▼]

In this paper, we propose a technique based on 3D information (also called depth or range) for the detection of humans. First, a background subtraction technique operates to detect the silhouettes of humans and objects moving in the scene. Then, a machine learning algorithm is used to predict if a silhouette annotated with depth matches a human silhouette or not. The complete method is designed to cope with defects introduced during the segmentation step. Results, obtained on computer generated data, show that 3D depth data is a valuable information for detecting humans in that it improves over techniques based on binary silhouettes. In our experiments, we have reached an accuracy of 99.9% thanks to the depth information. [less ▲]

A platform for the fast interpretation of movements and localization of users in 3D applications driven by a range camera

in Proceedings of the 3DTV Conference (2010, June)

Interactivity is one of the key challenges for immersive applications like gaming. Manufacturers have been working towards interfaces that are driven by a device (e.g. a Wiimote) or interfaces that are ... [more ▼]

Interactivity is one of the key challenges for immersive applications like gaming. Manufacturers have been working towards interfaces that are driven by a device (e.g. a Wiimote) or interfaces that are controlled by a camera with a subsequent computer vision module. Both approaches have unique advantages, but they do not permit to localize users in the scene with an appropriate accuracy. Therefore, we propose to use both a range camera and accurate range sensors to enable the interpretation of movements. This paper describes a platform that uses a range camera to acquire the silhouettes of users, regardless of illumination, and to improve the pose recovery with range information after some image processing steps. In addition, to circumvent the difficult process of calibration required to map range values to physical distances, we complete the system with several range laser sensors. These sensors are located in a horizontal plane, and measure distances up to a few centimeters. We combine all these measurements to obtain a localization map, used to locate users in the scene at a negligible computational cost. Our method fills a gap in 3D applications that requires absolute positions. [less ▲]

Introduction a l'analyse spectrale des reseaux microvasculaires du melanome cutane primitif.

in Pathologie Biologie (2010)

Cutaneous malignant melanoma represents one of the most dramatic skin cancers because its incidence is steadily growing in White populations. Of note, its metastatic risk and mortality dramatically ... [more ▼]

Cutaneous malignant melanoma represents one of the most dramatic skin cancers because its incidence is steadily growing in White populations. Of note, its metastatic risk and mortality dramatically increase when the primary neoplasm reaches about one millimeter thick. It is believed that angiogenesis and lymphangiogenesis associated with cutaneous melanoma potentially influence the neoplastic progression of the primary tumor and its metastases. In some instances, both the intratumoral and peritumoral microvasculature are correlated to booming of the tumoral growth fraction. In addition, the vascular network serves as a migration path for the intravascular and perivascular neoplastic spread. Hence, the quantification of the microvasculature might help establishing a prognostic factor of evolution. Among the available methods, spectral analysis of immunohistochemical sections highlighting vessels helps defining the microvasculature distribution. The benefit of using spectral analysis is discussed and the modalities of application of this analytical method are scrutinized. [less ▲]

Environmental dew point and skin and lip weathering.

in Journal of the European Academy of Dermatology & Venereology (2010), 24(5), 513-7

Xerosis represents a physiological response of the stratum corneum (SC) to environmental threats. The influence of the environmental dew point (DP) is not fully understood. This parameter is the air ... [more ▼]

Xerosis represents a physiological response of the stratum corneum (SC) to environmental threats. The influence of the environmental dew point (DP) is not fully understood. This parameter is the air temperature at which the relative humidity is maximum. This study aimed to assess the relationship between the environmental DP and the water-holding capacity of the skin and lower lip vermilion. For comparison, SC property was evaluated after occlusive application of cooled and uncooled hydrogel pads. Electrometric measurements using a dermal phase meter (DPM) device were performed on the back of the hands, the cheeks and the lower lip of 40 healthy menopausal women. Assessments were performed in the outdoor conditions during winter and spring. The same measurements were recorded after hydrogel pads, at room temperature or cooled to 4 degrees C, were placed for 15 min on the test sites. The environmental DP was recorded at each evaluation time. The SC water-holding capacity was discretely influenced by the DP. In the open-air environmental conditions, a positive linear relationship was found on the cheeks between the DP and DPM values. The relationship was weaker on the lips. Conversely, a consistent increase in DPM values was recorded immediately after removal of the cooled and uncooled hydrogel pads. The observations made in the open-air testing conditions are consistent with the predicted events following the Arrhenius law. By contrast, the combination of cooling and occlusion by the hydrogel pads is responsible for the reverse effect on the SC. [less ▲]

Real-time processing of depth and color video streams to improve the reliability of depth maps

Poster (2009, November)

Depth is a useful information in vision to understand the geometrical properties of an environment. Depth is traditionally computed in terms of a disparity map acquired by a stereoscopic system but, over ... [more ▼]

Depth is a useful information in vision to understand the geometrical properties of an environment. Depth is traditionally computed in terms of a disparity map acquired by a stereoscopic system but, over the last few years, several manufacturers have released single-lens cameras that directly capture depth information (also called range). This is an important technological breakthrough although range signals remain difficult to handle in practice, due to many reasons (low resolution, noise, low framerate, . . . ). Practitioners still struggle to use range data in their applications. The purpose of this paper is to give a brief introduction to range data (captured with a camera), discuss common limitations, and propose techniques to cope with difficulties typically encountered with range cameras. These techniques are based on a simultaneous view of the scene by a color and a depth camera that are combined to improve their interpretation in real time. [less ▲]

Combining Color, Depth, and Motion for Video Segmentation

in Computer Vision Systems (2009, October)

This paper presents an innovative method to interpret the content of a video scene using a depth camera. Cameras that provide distance instead of color information are part of a promising young technology ... [more ▼]

This paper presents an innovative method to interpret the content of a video scene using a depth camera. Cameras that provide distance instead of color information are part of a promising young technology but they come with many diff culties: noisy signals, small resolution, and ambiguities, to cite a few. By taking advantage of the robustness to noise of a recent background subtraction algorithm, our method is able to extract useful information from the depth signals. We further enhance the robustness of the algorithm by combining this information with that of an RGB camera. In our experiments, we demonstrate this increased robustness and conclude by showing a practical example of an immersive application taking advantage of our algorithm. [less ▲]

Impact du stress géoclimatique sur la peau.

in Dermatologie Actualité (2006), 100

Stress écologique et chronobiologique de la dérive géoclimatique.

in Revue Verviétoise d'Histoire Naturelle (2002), 59

Introduction à la paléopathologie. A la source des cancers chez les dinosaures

in Revue Médicale de Liège (2001), 56

L'appareil aptychial chez les ammonoïdes.

in Association des Géologues Amateurs de Belgique Minibul (2000), 33