Note on the Error Signal of Block Quantizers
Manfred Tasto, Paul A. Wintz · IRE Transactions on Communications Systems · 1973
We show that the error signal incurred by block quantizing stationary data is nonstationary under some conditions. Examples are presented that indicate that the mean square error is largest at the block edges. When block quantizers are used to encode pictures at low bit rates, this effect tends to make the block edges visible in the reconstructed picture.