Object-Based Multiple Sprite Coding of Unsegmented Videos using H.264/AVC

In spite of recent progress in the development of hybrid block-based video codecs, it has been shown that for low-bitrate scenarios there is still coding gain applying object-based techniques. We present a sprite-based codec, based on latest H.264 features using an inbuilt segmentation approach for scenes recorded by a rotating camera. The segmentation itself is built up on reliable background estimation from the sprite and short-term image registration. Moreover, we generate multiple sprites based on physical camera parameter estimation that overcome three of the main drawbacks of sprite coding techniques. First, the coding cost for the sprite image is minimized. Second, multiple sprites allow temporal background refresh and finally, registration error accumulation is kept very small. Experimental results show that this coding approach significantly outperforms latest H.264 extensions applying hierarchical B pictures.