In this paper, we describe an HDF5 schema created to support the efficient visualization of the large image cubes that will be produced by SKA Phase 1 and precursor radio telescopes. We demonstrate how the "HDF5-IDIA"schema's features can improve the performance of visualization software, using both low-level metrics and real-world tests of the schema's implementation in CARTA, an image viewer that is being developed to replace the existing CyberSKA and CASA viewers. (C) 2020 Elsevier B.V. All rights reserved.