Demand-driven image transmission with levels of detail and regions of interest

In this paper, we introduce a formal model which describes consistently lev els of detail and regions of interest for the progressive transmission of r aster images. This model serves as the foundation of a wavelet-based image communication framework which supports the progressive, redundancy-free tra nsmission of multiple, possibly overlapping regions of interest in an image . To support demand-driven transmission, we introduce a method for interlea ving control commands with the embedded bit stream. Since the dyadic wavele t decomposition allows the image resolutions in x and y direction to differ at most by a factor of two, we propose a new wavelet decomposition scheme which raises this number to a power of two for increased flexibility. We di scuss some applications including the rectangular fish eye view, a focus an d context display technique for raster images which efficiently uses this t ransmission method and saves screen real-estate. (C) 1999 Elsevier Science Ltd. All rights reserved.