Coronary angiogram video compression

The use of digitized information is rapidly gaining acceptance in radiological applications. Image compression plays an important role in the archiving and transmission of different digital diagnostic modalities. Currently block DCT based compression schemes (i.e. JPEG, MPEG) are usually used for telephone conferencing, cable video transmission and other non-medical applications. This scheme is not suitable for medical video sequences (like angiograms) because of block artifacts resulting from the block based DCT coefficient quantization. The image quality degrades severely with consecutive frame processing due to accumulation of errors across frames. We have developed a compression scheme for angiogram video sequence coding based on full frame wavelet coding. This full frame design exploits the local characteristics of the compensated difference signals (via block matching) and achieves a higher coding gain. At the same compression ratio, the proposed technique outperforms the block DCT method in image quality preservation. Our algorithm not only achieves a higher compression ratio but also maintains high fidelity for the reconstructed image which could be used in the PACS system and telediagnosis environment.