Cost-Distortion Optimization and Resource Control in Pseudo-Analog Visual Communications
Dian Liu, Jun Hui Wu, Hao Cui, Dongdong Zhang, Chong Luo, Feng Wu · IEEE Transactions on Multimedia · 2018
The rate-distortion in conventional digital systems is replaced by cost distortion in pseudo-analog systems where the cost consists of power and bandwidth. In this paper, we formulate the cost-distortion optimization problem in terms of a power-bandwidth pair versus distortion to bring an insight to pseudo-analog transmission. Using a divide-and-conquer strategy, the 3-D optimization problem of a power-bandwidth pair versus distortion is decomposed into two subproblems: power distortion and bandwidth distortion optimization. To solve the integer nonlinear optimization problem, we propose two prediction models that transform the partial summation of variances and the square roots of variances into continuous functions. The proposed models are used to derive the closed-form solutions for both optimization subproblems, and a tradeoff between power and bandwidth is discussed. Accordingly, the resource control algorithm is designed to allocate the fewest resources required to obtain specific video quality; power can be traded for bandwidth and vice versa. Our experimental results show that the proposed optimization models achieve stable perceptual video quality comparable to that of Groups of Pictures and use resources more efficiently than do SoftCast.