A Spatial RNN Codec for End-to-End Image Compression

Recently, deep learning has been explored as a promising direction for image compression. Removing the spatial redundancy of the image is crucial for image compression and most learning based methods focus on removing the redundancy between adjacent pixels. Intuitively, to explore larger pixel range beyond adjacent pixel is beneficial for removing the redundancy. In this paper, we propose a fast yet effective method for end-to-end image compression by incorporating a novel spatial recurrent neural network. Block based LSTM is utilized to remove the redundant information between adjacent pixels and blocks. Besides, the proposed method is a potential efficient system that parallel computation on individual blocks is possible. Experimental results demonstrate that the proposed model outperforms state-of-the-art traditional image compression standards and learning based image compression models in terms of both PSNR and MS-SSIM metrics. It provides a 26.73% bits-reduction than High Efficiency Video Coding (HEVC), which is the current official state-of-the-art video codec.