DC coefficient restoration in transform image coding
Wai Kuen Cham, R.J. Clarke · IEE Proceedings F Communications Radar and Signal Processing · 1984
In a transform coding system, a large number of bits have to be allocated to high-energy DC coefficients for both fine quantisation and good channel error immunity. Three schemes are proposed, in which the DC coefficients are not transmitted, but estimated at the receiver. This allows a reduction in bit rate, as well as the possibility of eliminating the serious effect of channel errors on those coefficients.