A scheme for spatial scalability using nonscalable encoders

We describe a scheme that achieves spatially scalable coding of video by employing nonscalable video encoders (e.g., MPEG-2 main profile), along with a downsampler and an upsampler. The scheme is illustrated for the case of coding video at two resolutions. The enhancement layer is coded in two steps by first exploiting the spatial redundancy and then exploiting the temporal redundancy. Hence, the scheme has a separable implementation. Results are presented for five different sequences, coded for three different combinations of base and enhancement layer bit rates. When MPEG-2 main profile is used for the nonscalable encoders, the results obtained are comparable to the performance of MPEG-2 spatial scalability profile.