FV polar coding for lossy compression with an improved exponent

Runxin Wang, Junya Honda, Hirosuke Yamamoto, Rongke Liu

Abstract: Polar codes achieve the rate-distortion bound for nonuniform sources and/or asymmetric distortion measures. However, the performance is not always near optimal for finite code length, especially for short code length. In this paper a new scheme for lossy source coding is proposed. In addition to polar coding, arithmetic coding is applied in the scheme. The source is first encoded by polar coding for lossy compression, then it is further compressed losslessly by arithmetic coding. It is shown that the scheme achieves the rate-distortion bound asymptotically with a good empirical performance. It is also shown that the distortion of the scheme has a better second-order exponent than those of the other polar coding schemes.