Task: Language Identification
Input (Spanish, English): This paper presents a generative model of video sequence data where the frames are assumed to be generated by a static background with a 2d sprite composited onto it at each timestep.  The sprite itself is allowed to dynamically change its appearance and location within the image from frame to frame.  This paper follows the VAE (Variational Autoencoder) approach, where a recognition/inference network allows them to recover the latent state at each timestep.  Some results are presented on simple synthetic data (such as a moving rectangle on a black background or the “Moving MNIST” data.  However, the results are preliminary and I suspect that the assumptions used in the paper are far too strong too be useful in real videos.  On the Moving MNIST data, the numerical results are not competitive to state of the art numbers.  The model itself is also not particularly novel and the work currently misses some relevant citations.  The form of the forward model, for example, could be viewed as a variation on the DRAW paper by Gregor et al (ICML 2014).  Efficient Inference in Occlusion-Aware Generative Models of Images by Huang & Murphy (ICLR) is another relevant work, which used a variational auto-encoder with a spatial transformer and an RNN-like sequence model to model the appearance of multiple sprites on a background.  Finally, the exposition in this paper is short on many details and I don’t believe that the paper is reproducible from the text alone.  For example, it is not clear what the form of the recognition model is…  Low-level details (which are very important) are also not presented, such as initialization strategy.
Output (English): en