Scandolo, LeonardoBauszat, PabloEisemann, ElmarEitan Grinspun and Bernd Bickel and Yoshinori Dobashi2016-10-112016-10-1120161467-8659https://doi.org/10.1111/cgf.13035https://diglib.eg.org:443/handle/10.1111/cgf13035Multiresolution Hierarchies (MH) and Directed Acyclic Graphs (DAG) are two recent approaches for the compression of highresolution shadow information. In this paper, we introduce Merged Multiresolution Hierarchies (MMH), a novel data structure that unifies both concepts. An MMH leverages both hierarchical homogeneity exploited in MHs, as well as topological similarities exploited in DAG representations. We propose an efficient hash-based technique to quickly identify and remove redundant subtree instances in a modified relative MH representation. Our solution remains lossless and significantly improves the compression rate compared to both preceding shadow map compression algorithms, while retaining the full run-time performance of traditional MH representations.I.3.7 [Computer Graphics]Three Dimensional Graphics and RealismColorshadingshadowingand textureI.4.2 [Computer Graphics]Compression (Coding)Exact coding10.1111/cgf.13035383-390