Shape and motion from image streams under orthography: a factorization method
International Journal of Computer Vision
A Paraperspective Factorization Method for Shape and Motion Recovery
IEEE Transactions on Pattern Analysis and Machine Intelligence
Efficient Region Tracking With Parametric Models of Geometry and Illumination
IEEE Transactions on Pattern Analysis and Machine Intelligence
A Multibody Factorization Method for Independently Moving Objects
International Journal of Computer Vision
Feature Detection with Automatic Scale Selection
International Journal of Computer Vision
On Active Camera Control and Camera Motion Recovery with Foveate Wavelet Transform
IEEE Transactions on Pattern Analysis and Machine Intelligence
Zoom tracking and its applications
Machine Vision and Applications
Affine Real-Time Face Tracking Using a Wavelet Network
RATFG-RTS '99 Proceedings of the International Workshop on Recognition, Analysis, and Tracking of Faces and Gestures in Real-Time Systems
A Closed-Form Solution for Paraperspective Reconstruction
ICPR '00 Proceedings of the International Conference on Pattern Recognition - Volume 1
Affine Real-Time Face Tracking using Gabor Wavelet Networks
ICPR '00 Proceedings of the International Conference on Pattern Recognition - Volume 1
Automatic Face Region Tracking for Highly Accurate Face Recognition in Unconstrained Environments
AVSS '03 Proceedings of the IEEE Conference on Advanced Video and Signal Based Surveillance
Information Theoretic Focal Length Selection for Real-Time Active 3-D Object Tracking
ICCV '03 Proceedings of the Ninth IEEE International Conference on Computer Vision - Volume 2
Reactive Control of Zoom while Fixating Using Perspective and Affine Cameras
IEEE Transactions on Pattern Analysis and Machine Intelligence
Fusion of Omnidirectional and PTZ Cameras for Accurate Cooperative Tracking
AVSS '06 Proceedings of the IEEE International Conference on Video and Signal Based Surveillance
Resolution vs. tracking error: zoom as a gain controller
CVPR'03 Proceedings of the 2003 IEEE computer society conference on Computer vision and pattern recognition
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To achieve size preserving tracking, in addition to controlling the camera's pan and tilt motions to keep the object of interest in the camera's field of view (FOV), the camera's focal length is adjusted automatically to compensate for the changes in the target's image size caused by the relative motion between the camera and the target. The estimation accuracy of these changes determines the effectiveness of the resulting zoom control. The existing method of choice for real-time target scale estimation applies structure from motion (SFM) based on the weak perspective projection model. In this paper we propose a target scale estimation algorithm with a linear solution based on the more advanced paraperspective projection model, which improves the accuracy of scale estimation by considering center offset. Another key issue in SFM based algorithms is the separation of target and background features, especially when composite camera (pan/tilt/zoom) and target motions are involved. This paper designs a fast target feature separation/grouping algorithm, the 3D affine shape method. The resulting separation automatically adapts to the target's 3D geometry and motion and is able to accommodate a large amount of off-plane rotation, which most existing separation/grouping algorithms find difficult to achieve. Experimental results illustrate the effectiveness of the proposed scale estimation and feature separation algorithms in tracking translating and rotating objects with a PTZ camera while preserving their sizes. In comparison with the leading size preserving tracking algorithm described by Tordoff and Murray, our algorithm is able to reduce the cumulative tracking error significantly from 17.4% to 3.3%.