Quality-progressive coding for high bit-rate background frames on surveillance videos

A remarkable compress performance was achieved in the surveillance video coding when high-quality reconstructed background frames were referenced in long-term. However, the high-quality reconstructed background frames lead to bursting bit-rate peaks in the video transmission, which may cause obvious communication delay or buffer overflow. In order to address this problem, the paper proposes a quality-progressive coding algorithm for smoothing the bursting peaks caused by high-quality reconstructed background frames. Instead of a single high-quality reconstructed background frame, we divide the background frame into a set of frames, which include the basic reconstructed background frame of normal-quality (basic part) and a series of reconstructed residual frames (residual part), for transmission. Moreover, the modeled background frame and the residual frames should be encoded into the bit-stream and transmitted every several frames, and the coding bits of two frame types above should be limited to the target range of coding bits, which is based on the channel capacity, so that avoids the bursting bit-rate peak and the transmission delay. Background frames are reconstructed by summing up the basic part and reconstructed residual frames one by one, and the last reconstructed background frame becomes a high-quality reconstructed background frame. Of course, each reconstructed background frame act as a prediction reference for its subsequent frames. Experimental results on an opening dataset, PKU-SVD-A, show that the proposed approach can smooth the bit-rate of high-quality reconstructed background frame in surveillance video coding, and achieve 0.57% bit-rate saving on average compared with HEVC-S.