3D subband coder for very low bit rates
A video coder based on 3D subband coding system (SBC) targetted for very low bit rate applications is developed and simulated. It employs QMF subband analysis to decompose an input sequence into 4 temporal bands. A low-complexity block-based motion detection scheme is then applied to all bands followed by motion classification and reduced motion search on the baseband which is H.261-like coded and the high temporal bands are vector-quantised (VQ) with a bank of codebooks (switched codebook VQ). Simulations are performed at 9.6 kbit/sand 14.4 kbit/s at 5 frame/s for QCIF format and results showed that it achieved better performance than the ITU-T short-term reference model SlM3 coder at similar bit rates. Subjective evaluation favours the 3D SBC coder because it does not suffer from 'blocking' artifacts.<<ETX>>