This paper deals with visual servoing for a pan and tilt camera embedded in a drone. Video is transmitted to the ground where images are processed on a PC, and turret controls are sent back to the drone. The objective is to track any fixed object on the ground without knowledge about shape or texture and to keep it centered in the image. In order to achieve this task an algorithm that combines ...

In this paper, we develop a hierarchical global motion estimation/compensation system which is used to improve the block-based motion compensation in the current low bitrate video coding standard H.263. The system first detects the background motion by examining the local motion information using hierarchical block matching and global motion estimation algorithm. If the background motion exists...

In the H.263 Version 2 (H.263+) coding standard, the global motion compensation can be introduced by using Reference Picture Resampling (Annex. P) syntax. Such an application requires that the global motion parameters be estimated automatically. In this paper, we propose a global motion estimation algorithm based on the Taylor Expansion Equation and robust regression technique using probabilist...

Overlapped block motion compensation or B-frames are examples of multihypothesis motion compensation where several motion-compensated signals are superimposed to reduce the bit-rate of a video codec. This paper extends the wide-sense stationary theory of motion-compensated prediction (MCP) for hybrid video codecs to multihypothesis motion compensation. The power spectrum of the prediction error...

This paper describes a new approach to the problem of motion estimation for the coding of image sequences. The goal is to obtain an eecient description (parametrization) of temporal variations between two successive images in a sequence. To achieve this we propose to use the standard hypothesis of luminance constancy along a motion trajectory simultaneously introducing a polynomial representati...

In this paper we address the problem of motion estimation failure in degraded image sequences. This failure is caused by some complex events that take place in the image. As a result, the sequence of operations that rely on the motion estimation process, such as motion compensation and motion picture restoration, will fail as well. The statistical analysis of the complex event areas indicates t...

Severe environment in deep ocean affects operating reliability and security of coring drill. Adopting heave motion signal measured by accelerometer to confirm heave compensation of coring drill, the compensation control method is proposed using disturbance observer to restrain the disturbance. Then, the disturbance observer is designed. The heave motion simulation for coring drill is done with ...

We describe new algorithms for multi{frame structure from motion from tracked point features. The algorithms are essentially linear and give accuracies similar to those of a maximum{likelihood estimate. For the common situation where the calibration is xed and approximately known, we experimentally compare the fully projective versions of our algorithms to mixed projective/Euclidean strategies....

This paper addresses the application of active contours or snakes for tracking of contours in image sequences. We propose to use the dynamic programming implementation of the snakes in order to restrict the possible candidates for a given snaxel to those that have a high correlation with the corresponding snaxel in the previous frame. Besides, we claim that, in tracking applications, the motion...