VIDEO COMPRESSION OF CORONARY ANGIOGRAMS BASED ON DISCRETE WAVELET TRANSFORM WITH BLOCK CLASSIFICATION

A new method of video compression for angiographic images has beers de veloped to achieve high compression ratio (similar to 20:1) while elim inating block artifacts which leads to loss of diagnostic accuracy. Th is method adopts motion picture experts group's (MPEG's) motion compen sated prediction to takes advantage of frame to frame correlation. How ever, in contrast to MPEG, the error images arising from mismatches in the motion estimation are encoded bg discrete wavelet transform (DWT) rather than block discrete cosine transform (DCT). Furthermore, we de veloped a classification scheme which label each block in an image as intra, error, or background type and encode it accordingly. This hybri d coding can significantly improve the compression efficiency in certa in cases. This method can be generalized for any dynamic image sequenc es applications sensitive to block artifacts.