39 research outputs found
Relaxed Spatio-Temporal Deep Feature Aggregation for Real-Fake Expression Prediction
Frame-level visual features are generally aggregated in time with the
techniques such as LSTM, Fisher Vectors, NetVLAD etc. to produce a robust
video-level representation. We here introduce a learnable aggregation technique
whose primary objective is to retain short-time temporal structure between
frame-level features and their spatial interdependencies in the representation.
Also, it can be easily adapted to the cases where there have very scarce
training samples. We evaluate the method on a real-fake expression prediction
dataset to demonstrate its superiority. Our method obtains 65% score on the
test dataset in the official MAP evaluation and there is only one misclassified
decision with the best reported result in the Chalearn Challenge (i.e. 66:7%) .
Lastly, we believe that this method can be extended to different problems such
as action/event recognition in future.Comment: Submitted to International Conference on Computer Vision Workshop
Iterative technique for 3-D motion estimation in videophone applications
In object based coding of facial images, the accuracy of motion and depth parameter estimates strongly affects the coding efficiency. We propose an improved algorithm based on stochastic relaxation for 3-D motion and depth estimation that converges to true motion and depth parameters even in the presence of 50% error in the initial depth estimates. The proposed method is compared with an existing algorithm (MBASIC) in case of different number of point correspondences. The simulation results show that the proposed method provides significantly better results than the MBASIC algorithm
New approach to holographic video imaging: principles and simulations
As the importance of 3-dimensional information displays in many fields increases, more attention is given to holographic displays. Different kinds of holographic displays are reported in the literature, but the resolution of the available display media is not sufficient to support the extraordinary spatial detail of holograms. In this paper, we propose a new acousto-optical holographic display device which solves significantly the display resolution and the refreshing problems that are common to available holographic displays. The technique is based on the reproduction of the hologram using traveling surface waves. The SAW device that is used as the medium of display has an array of electrodes attached to it. An electrical signal applied to one of these electrodes generates an acoustical wave propagating on the surface of the crystal where the electrodes are the sources. If signals are applied to all of the electrodes simultaneously, propagating waves from the electrodes superpose to form a time-varying surface field pattern on the crystal. This pattern, at a specific time, forms the hologram. The signals which should be applied to the electrodes, in order to have a specified field pattern on the crystal at a specified time instant are found through a mathematical inversion relation. The inversion relationship is derived from the underlying physics. Computer simulations of the proposed TV display show that the proposed system will work as desired. In addition, our preliminary studies show that the proposed system can be constructed with the available acoustical, optical, electronic technology, and with the application of digital signal processing techniques