The Coding Rate Control of Consistent Perceptual Video Quality in H.264 ROI

The video coding perceptual quality at low bit rates was enhanced by a rate control scheme that achieves a better trade off between consistent quality and smooth buffer occupancy. A proportional integral technique was used for the frame level rate control. The motion extrapolated coding complexity propagation model was used to allocate bits between the region of interest (ROI)and other regions while smoothing distortion in the ROI using rate and distortion optimized macro block level bit allocation. Simulations show that the algorithm reduces ROI distortion fluctuation by 35.5% to 57.1% compared with the rate control by the traditional JM algorithm at the same bit rate.