Optimum bit allocation for FGS video coding

This paper proposes a new bit allocation scheme for fine-granular-scalability (FGS) video coding, through which we can achieve better video quality. Different from traditional rate-distortion (R-D) optimization schemes, we consider the characteristics of the bit-plane (BF) coding method. To be specific, we first find the approximate linear relationship between the bit rate of the FGS-layer and the percentage of nonzero binary-scaled coefficients (NZBC) in each BF; second, with mathematical justification, we derive an optimal strategy by analyzing the overall distortion with respect to NZBC. Finally, we perform our optimum bit allocation (OBA) on a FGS coder. Experimental results prove that our scheme can achieve smooth video quality with a higher average PSNR gain compared with uniform bit allocation (UBA). And for certain frames with lower PSNR, it has a gain of up to 3 dB. It is highly source-independent and more robust compared with previous bit allocation schemes.