Similarity motion estimation and active tracking through spatial-domain projections on log-polar images

To cope with the huge amount of visual data in the environment, foveal sensing is not only an elegant biological solution, but also an appropriate mechanism in computer-based vision of artificial agents such as robots. An extremely important visual behavior in active vision systems is that of actively tracking moving targets, which is a problem closely related with foveal vision. The work described in this article has precisely to do with active tracking with space-variant images. The two main components of the proposed algorithm are the log-polar image format, and a projection-based motion estimator, whose joint use results in an efficient and effective active tracking scheme. For the successful real-time performance of the proposed approach, it is very important to have an appropriate combination of: (i) an efficient motion estimation technique, (ii) an adequate image representation, and (iii) the dynamic nature of purposive vision.