| Some images contain regions which are more important than other. Compression methods which are capable of delivering higher reconstruction quality for the important parts are attractive in this situation. For medical images, only small portion of the image might be diagnostically useful, but the cost of a wrong interpretation is high. Methods which deliver lossless compression within the regions of interest, and lossy compression elsewhere in the image, might be the key to providing efficient and accurate image coding to the medical community. We propose and compare some new lossless region of interest compression methods. These methods are based on the Embedded zerotree wavelet coding that is used according to two different approaches. One applied to the whole image and the other applied to a subdivision of the image in equal blocs. |
