Functionality for storing and modifying multi-resolution texture atlases is provided so that applications can expose methods to enable users to access and browse a collection that includes multiple multi-resolution images. The images are stored as thumbnails in a texture atlas having different levels of detail in which the levels are arranged in an image pyramid that includes multiple tiles that are each stored as separate files. The thumbnails are spatially storable as textures in the texture atlas using a fractal layout (which in one illustrative example is a Morton layout) that enables images to be efficiently packed in the tiles. The fractal layout ensures that no more than one tile stores less than a fully packed texture at each level of detail. The same packing order scales across each level of detail in the texture atlas so that layout information is stored for the individual images in the collection only once.