Jacques Domey

Facial image synthesis using skin texture recording

A significant issue in synthesizing realistic faces is the representation of skin grain and wrinkles. This paper describes a new approach based on the registered body of a real person. This recording allows simultaneously registering of the 3-D coordinates of a point and the corresponding reflected intensity. Using a 4-D B-spline surface to reconstruct the face, we come close to achieving a photographic result.

Real world modelling through high resolution digital 3D imaging of objects and structures

Abstract This paper summarises the results achieved from a number of laser scanning experiments performed in our laboratories and on remote sites. The potential of this technology for imaging applications and as an input to virtualised reality environments is discussed. Parameters to be considered for this type of activity are related to the design of laser scanners with adequate depth of field, image resolution, shape reproduction fidelity, registered colour information, robustness to ambient light interference and scanning strategies. The first case reviewed is an application geared towards improving access to art collections belonging to museums. A number of digital 3D models acquired in Italy in 1997–1998 are presented, e.g. marble statue from G. Pisano (circa 1305). The second case aims at digitising large structures. Examples of a large sculpture located outside of the Canadian Museum of Civilisation in Hull, Canada and the Orbiter Docking System (ODS) located at the Kennedy Space Center in Florida, are presented.

Optical range image acquisition for the navigation of a mobile robot

A very compact optical range sensor is described which is to be used for the acquisition of the range information for the navigation of a mobile platform. A short review of the techniques currently used to acquire range data for a mobile vehicle is included. Some advantages and disadvantages of the different methods are presented. Emphasis is placed on a possible short-to-medium-term solution of the problem of robot navigation. A short description of the optical principle of the range sensor BIRIS, its real-time implementation on a commercially available image processing system, and its performance are presented. The high immunity of the sensor to ambient illumination and external perturbations is also demonstrated. Experimental results and a technique for the detection of the free space surrounding the vehicle using the range data are given.<<ETX>>

FACE RECOGNITION WITH RANGE IMAGES AND INTENSITY IMAGES

The surface normal of a range image of a face can be decomposed into three components. The combinations of these three weighted components produce 2-D intensity images with different illuminations. A phase-only vector filter is designed based on these normal components. With such a vector filter, the face recognition can be performed between range face and range face, or between range face and intensity face. This kind of recognition is less sensitive to the changes of illumination of the input face.

Registered intensity and range imaging at 10 mega-samples per second

A video rate laser range finder based on the autosynchronized scanning approach is presented. This range camera simultaneously provides range and intensity information of a scene in EIA-RS-170 format. A spatial resolution of 420 horizontal lines each having 512 pixels was achieved at a rate of 30 images per second. A wide dynamic range in intensity (16 bits) coupled with drift compensation allows this sensor to achieve a range resolution of 8 bits. The volume of view is 50 x 50 x 50 mm3.

A Very Compact Real Time 3-D Range Sensor For Mobile Robot Applications

A very compact 3-D range sensor, ideal for robotic applications and especially for mobile robots is described. The principle of this sensor is based on the use of a double aperture mask in place of the diaphragm of a standard camera lens. The basic optical principle of the system and the image processing algorithms to extract and compute the 3-D coordinates of the scene are described. A first prototype used to evaluate the characteristics of the range sensor and to acquire panoramic images of a room is shown. Performances and experimental results are presented.

Compact three-dimensional camera for robot and vehicle guidance

Abstract A very compact 3-D range sensor for robot and vehicle guidance is described. A dual aperture mask in a camera lens is used to transform a small commercially available CCD video camera into a ranging sensor. An active system using a projected laser beam provides a 360° range map which can be used to plan trajectories, either for robots or autonomous vehicles. Good quality panoramic intensity and 3-D images were obtained. Accuracy, speed of acquisition, and cost are discussed. Experimental results are presented.

Registered 3D-texture imaging

In this paper we are presenting synthesis of faces obtained by means of a registered recording of a human face. This recording allows to get the geometrical coordinates and the corresponding intensity of each sample point at the same time. With these data organized in a 4-dimensional B-Spline surface, we are able to greatly improve the realistic quality of the reconstructed picture, coming close to a photographic result.

Signal Processing Requirements For A Video Rate Laser Range Finder Based Upon The Synchronized Scanner Approach

This article presents the results of an analysis and a discussion of the signal processing requirements for a video rate laser range finder. The lateral effect photodiode is chosen as the position detector for its speed, ease of use, and cost trade-offs over other sensors. Two models are presented for this sensor: the transmission line and the lumped elements. Both are investigated for possible use in circuit analysis. The latter model is selected, although it is not as accurate as the first one. However, it can yield valuable results able to show dependences between system parameters. The results of a linear circuit analysis give some trade-offs for optimum current to voltage conversion for fast response lateral effect photodiodes. Also, a discussion of the merits of techniques for position calculation, to increase the dynamic range of the system and reduce both costs and circuit complexity, is presented.

Laser range imaging in archaeology: issues and results

Archaeology is emerging as one of the key areas of applications for laser range imaging. This particular context imposes a number of specific constraints on the design and operations of range sensors. In this paper, we discuss some of the issues in designing and using laser range sensor systems for archaeology. Results obtained on remote archaeological sites will serve to illustrate these considerations.