It should be possible to expand the SPARSEIMAGE file to a common ISO with the Apple Disk Utility. Probably can also be done using the DropDMG software.
Convert Apple MAC OS X sparse disk image to CD/DVD/HD DVD/Blu-ray disc ISO binary image.
We found 2 software records in the database related to .sparseimage to .iso file format conversion.
Apple macOS / Mac OS X software - convert sparseimage to iso on OS X
A disk mounting utility from Mac OS X
Convert from sparseimage file format
|Yes, Apple Disk Utility supports iso file conversion as a target file type.||Yes||Yes||iso editor||Yes||No||No||Yes|
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned sparseimage to iso. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A program for creating Mac OS X disk images