Deep Learned Frame Prediction for Video Compression.

Abstract

Motion compensation is one of the most essential methods for any video compression algorithm. Video frame prediction is a task analogous to motion compensation. In recent years, the task of frame prediction is undertaken by deep neural networks (DNNs). In this thesis we create a DNN to perform learned frame prediction and additionally implement a codec that contains our DNN. We train our network using two methods for two different goals. Firstly we train our network based on mean square error (MSE) only, aiming to obtain highest PSNR values at frame prediction and video compression. Secondly we use adversarial training to produce visually more realistic frame predictions. For frame prediction, we compare our method with the baseline methods of frame difference and 16x16 block motion compensation. For video compression we further include x264 video codec in the comparison. We show that in frame prediction, adversarial training produces frames that look sharper and more realistic, compared MSE based training, but in video compression it consistently performs worse. This proves that even though adversarial training is useful for generating video frames that are more pleasing to the human eye, they should not be employed for video compression. Moreover, our network trained with MSE produces accurate frame predictions, and in quantitative results, for both tasks, it produces comparable results in all videos and outperforms other methods on average. More specifically, learned frame prediction outperforms other methods in terms of rate-distortion performance in case of high motion video, while the rate-distortion performance of our method is competitive with that of x264 in low motion video.