Compression of medical volumetric data in a video-codec framework

Abstract

We propose to use video-codec framework for the compression of volumetric medical images by treating interslice variations as 'motion' of the tissues. As compression is necessary for telemedicine and archive, such an approach needs only slight modifications of existing codecs and is able to re-use most of the existing software and hardware. This is our main motivation and we seek modifications of the MPEG codec. An obvious modification is to replace block matching (BM) by more sophisticated methods. Specifically, we use the affine transformation (AT) on triangular patches. We implemented and compared our scheme with a simplified MPEG-1 encoder under identical parameters on a set of MRI images of a human hand. The blockiness is reduced dramatically and structures are better preserved. The images also appear less granular and show improvements of several dB in SNR. We expect further improvements when more features of MPEG codec are incorporated in our ongoing work.