Achraf Ben-Hamadou

Learn More
Bladder cancer is widely spread in the world. Many adequate diagnosis techniques exist. Video-endoscopy remains the standard clinical procedure for visual exploration of the bladder internal surface. However, videoendoscopy presents the limit that the imaged area for each image is about nearly 1 cm. And, lesions are, typically, spread over several images.(More)
Video-endoscopy is the standard clinical procedure for visual exploration of internal walls of hollow organs. For the bladder, the lesion diagnosis is complex because the endoscopic images are bi-dimensional and cover only small bladder areas. 3D endoscopes, based on stereoscopic active vision principles, were recently proposed and validated. This paper(More)
This contribution deals with the calibration of active stereoscopic systems consisting of a camera and a structured light projector. Usually, expensive equipments like precise calibration pieces or dedicated positioning devices are used for the projector calibration. We developed a flexible calibration method using only a planar target as calibration board(More)
Endoscopy is a standard imaging modality commonly used in different medical fields like lesion diagnosis in hollow organs or mini-invasive surgery. Meanwhile, endoscopic data suffer from the fact that each image of a video-sequence only corresponds to a small 2D field of view. This paper presents a mosaicing algorithm leading to visually coherent large(More)
Video endoscopy is one of the standard clinical procedures for visually detecting lesions on the internal wall of human bladders. In order to facilitate the diagnosis, it is helpful to build panoramic maps by registering consecutive images from the video sequence. We show how to efficiently reduce the computation time of graph cut based image registration(More)
This paper presents a new method for 3D face pose tracking in arbitrary illumination change conditions using color image and depth data acquired by RGB-D cameras (e.g., Microsoft Kinect, Asus Xtion Pro Live, etc.). The method is based on an optimization process of an objective function combining photometric and geometric energy. The geometric energy is(More)
Visual speech recognition remains a challenging topic due to various speaking characteristics. This paper proposes a new approach for lipreading to recognize isolated speech segments (words, digits, phrases, etc.) using both of 2D image and depth data. The process of the proposed system is divided into three consecutive steps, namely, mouth region tracking(More)
In this paper we present a method dedicated to hand tracking in sign language scenes using particle filtering. A a new penalisation method based on the optical flow mechanism is introduced. Generally, particle filters require the use of a reference model. In this paper we have introduced a new method based on a dictionary of visual references of hand to(More)