Low-complexity rate control in video coding based on bi-geometric transparent composite models

Bi-geometric transparent composite models (BGTCM) are used to model distributions of transform coefficients in HEVC (High efficiency video coding). Both Kullback-Leibler divergence and χ² test show that, for both original and quantized transform coefficients in HEVC, BGTCMs provide better modelling performance than popular Laplacian and Cauchy models. Based on BGTCMs, a rate control algorithm is proposed for HEVC. Experimental results using the HEVC reference software show that the proposed algorithm achieves better performance in constant-bit-rate control than previous rate control algorithms based on Laplacian models.