Title :
Variable block rate and blockwise spectral adaptation in cosine transform image coding
Author :
Pearlman, William A.
Author_Institution :
Dept. of Electr. Comput. & Syst. Eng., Rensselaer Polytech. Inst., Troy, NY, USA
Abstract :
A block discrete-cosine transform coding scheme is implemented with a different rate assignment to each block for the purpose of maintaining a constant distortion per block. A spectral estimate is calculated for every block. Overhead rate and computation for adaptation are kept to a reasonable level through characterization of the block´s estimated spectrum by a one-dimensional autoregressive model. Simulations with natural and multimodality medical images provide reconstructions with nearly uniform block distortion and very high visual and measurable quality at low rates
Keywords :
encoding; picture processing; spectral analysis; transforms; blockwise spectral adaptation; cosine transform image coding; medical images; one-dimensional autoregressive model; rate assignment; spectral estimate; variable block rate; Discrete cosine transforms; Discrete transforms; Distortion measurement; Equations; Image coding; Karhunen-Loeve transforms; Maintenance engineering; Modeling; Quantization; Systems engineering and theory;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 1988. ICASSP-88., 1988 International Conference on
Conference_Location :
New York, NY
DOI :
10.1109/ICASSP.1988.196699
