The user interface is the central element of a telepresence robotic system and its visualization modalities greatly affect the operator's situation awareness, and thus its performance. Depending on the task at hand and the operator's preferences, going from ego- and exocentric viewpoints and improving the depth representation can provide better perspectives of the operation environment. Our system, which combines a 3D reconstruction of the environment using laser range finder readings with two video projection methods, allows the operator to easily switch from ego- to exocentric viewpoints. This paper presents the interface developed and demonstrates its capabilities by having 13 operators teleoperate a mobile robot in a navigation task.

Intelligence has been an object of study for a long time. Different architectures try to capture and reproduce these aspects into artificial systems (or agents), but there is still no agreement on how to integrate them into a general framework. With this objective in mind, we propose an architectural methodology based on the idea of intentional configuration of behaviors. Behavior‐producing modules are used as basic control components that are selected and modified dynamically according to the intentions of the agent. These intentions are influenced by the situation perceived, knowledge about the world, and internal variables that monitor the state of the agent. The architectural methodology preserves the emergence of functionality associated with the behavior‐based paradigm in the more abstract levels involved in configuring the behaviors. Validation of this architecture is done using a simulated world for mobile robots, in which the agent must deal with various goals such as managing its energy and its well‐being, finding targets, and acquiring knowledge about its environment. Fuzzy logic, a topologic map learning algorithm, and activation variables with a propagation mechanism are used to implement the architecture for this agent.

This paper presents a new compression scheme for interlaced stereoscopic sequences which differentiates between a region of fixation and a peripheral area, and thereby compacts the stereoscopic information into the spectral space of a monocular video channel. Spectral compression is achieved by avoiding transmitting high-frequency information over the entire images, but only within and around the region where the observer acuity is the highest. The proposed approach consists of decomposing the left and right fields of the stereoscopic pairs into low-pass and high-pass components. High-frequency components are then limited to a fixation region, thus allowing a reduction of their spectral extent. A composite video signal is then formed by positioning the different components into the available spectral space through filtering and modulation. The approach is compatible with the NTSC standard in the sense that the same color subcarrier and the same spectral region are used for the chrominance components. Strategies are proposed for the estimation of the fixation region, based upon a psychophysical study on visual strategies during depth discrimination tasks.

Video line doubling can be realized using time-space interpolation filters. To improve their performances for moving diagonal lines, we have developed a fuzzy edge-direction detector. This fuzzy detector works by identifying small pixel variations in five orientations (0/spl deg/, /spl plusmn/45/spl deg/, and /spl plusmn/60/spl deg/) and by using rules to infer the prevailing direction. This direction is then used to spatially rotate the interpolation filter. For the fuzzy detector, three fuzzy sets are used to characterize the inputs, and two rule bases have been validated. This article presents the characteristics of the fuzzy edge-direction detector along with the methodology used for fuzzy sets positioning. Detection and interpolation results are also presented.

This paper describes a new spectral compaction method for interlaced stereoscopic sequences which combines the stereo information into the spectral space of a single NTSC video channel. The method makes use of the variable spatial and stereoscopic resolution of the human visual system and relies upon the determination of an area of fixation. Spectral compaction is achieved by retaining only the high-frequency information associated with this area. A composite video signal is formed by combining the lowpass, highpass and chrominance components of both channels into the available spectral space by means of modulation and filtering operations. Compatibility of the composite video signal with the NTSC standard is ensured by using the same colour subcarrier for the chrominance components of one channel and a second subcarrier whose phase is inverted on alternate fields to place the chrominance components of the second channel into the Fukinuki holes. Good quality results are obtained with relatively simple separable FIR filters.

This paper describes a new compression method for interlaced stereoscopic image sequences, which compacts the stereo information into the spectral space of a single NTSC channel. The left and right fields of the stereoscopic pairs are each decomposed into a lowpass and a highpass components. High-frequency components are limited to an area of fixation, thus allowing a reduction of their spectral extent. A composite video signal is then formed by positioning the different components in the available spectral space through filtering and modulation. Compatibility of the produced signal with the NTSC standard is ensured by using the same spectral region for the chrominance information and the same colour subcarrier. Good quality results are obtained with relatively simple 2D separable spatial filters at a reasonable computational cost.

The relation between time-limiting and sequency-band-limiting in finite Walsh transforms is considered. It is found that optimum solutions (energy ratio equal to unity) are a nontrivial linear combination of[TM/N]successive orthogonal block pulses of durationR = NM^{-1}. Optimum solutions for bandpass signals are pointed out. Extension to the continuous-time domain is also discussed.

A general expression for oo such that cal (k,θ+θ0)= sal (k,θ) is obtained and a proof is given. This new form of θ0 is more direct and thus easier to use than other existing formulas.