1. A computer-readable storage medium for storing a still image, comprising: a plurality of decomposition levels representing the still image at increasingly higher levels of resolution, the decomposition levels being arranged in order of increasing levels of resolution; individual decomposition levels each comprising a plurality of subimages which allow reconstruction of an image representation of the still image, said subimages having rows of subimage values corresponding to rows of said image representation; said rows of subimage values being arranged within each particular decomposition level in row blocks, each row block containing a row of subimage values from different subimages of the particular decomposition level, wherein the subimage values in each row block correspond to a common image representation row; wherein said arrangement of subimage values supports retrieval of the subimage values in an order that facilitates reconstruction of the still image on a row-by-row basis, at increasingly higher levels of resolution.