Title :
The LOT: transform coding without blocking effects
Author :
Malvar, Henrique S. ; Staelin, David H.
Author_Institution :
PictureTel Corp., Peabody, MA, USA
fDate :
4/1/1989 12:00:00 AM
Abstract :
An exact derivation of an optimal lapped orthogonal transform (LOT) is presented. The optimal LOT is related to the discrete cosine transform (DCT) in such a way that a fast algorithm for a nearly optimal LOT is derived. Compared to the DCT, the fast LOT requires about 20-30% more computations, mostly additions. An image coding example demonstrates the effectiveness of the LOT in reducing blocking effects; the LOT actually leads to slightly smaller signal reconstruction errors than does the DCT.<>
Keywords :
encoding; errors; fast Fourier transforms; optimisation; picture processing; blocking effects; discrete cosine transform; fast algorithm; image coding; optimal lapped orthogonal transform; signal reconstruction errors; transform coding; Bit rate; Discrete cosine transforms; Discrete transforms; Filtering; Image coding; Karhunen-Loeve transforms; Low pass filters; Quantization; Speech coding; Transform coding;
Journal_Title :
Acoustics, Speech and Signal Processing, IEEE Transactions on
