THE USE OF PREDICTIVE CODING FOR EFFECTIVE COMPRESSION OF VECTOCARDIOGRAMS

The paper presents a sequence coding technique applied to the compression of vectocardiograms. The loops corresponding to P, QRS and T waves in an appropriate temporal window form Groups Of Beats (GOB). All inner loops in a group are predicted using the neighboring loops' values and the prediction error is subject to encoding. The lossless Huffman coding and the lossy DCT-based coding are considered and discussed in the paper. Detailed study of various compression aspects is provided thanks to the numerical experiment carried out for a wide range of parameters. Results of both methods are quite promising: the method preserving loops identity reduces the data volume 3 times (i. e. 2000 bps) and the lossy version reaches the reduction ratio of 4.15 times at a price of 5% PRD distortions.