Every Mac user has had some experience with DMG files, since they are the primary file format by which applications on Mac OS X are distributed. A DMG file is a compressed image file, which can also be password protected, and was developed by Apple specifically to facilitate distribution of software over the internet where size (bandwidth) and security are primary concerns. Even though DMG files are mostly specific to Mac OS X, sometimes they contain data which is either OS agnostic, or data which you might need to burn on a DVD, or share with other people whom you don’t know. In such a scenario, you might want to convert this DMG image file to a standard binary image format such as ISO, BIN or IMG.
DMGExtractor is such a tool that may help you out. Developed by Erik Larsson, its a Java standalone application which can be used via a minimalistic UI, or via the command line. For the benefit of the common Mac user, I will cover only the GUI version.
When you first launch the standalone, you will see that this is indeed a functionality-centered tool, because the developer did not work at all on making the UI pretty or even conventional. In fact there is hardly any UI at all. You will be greeted with this alert message:
The next screen is the one where you select the DMG file you want to convert/extract:
Once you choose the required DMG file, a prompt asks you if you want to simulate the extraction or extract it to an actual binary format. Select ‘No’ for the former, and ‘Yes’ for the latter.
Once you select ‘Yes’, another dialog pops up which asks you for the name, output location and output format of the image you want. You can select from the following options: