Convert a disk image to another format using Disk Utility on Mac
You can convert the image format and encryption of a disk image.
For example, if you create a read/write disk image but later want to prevent changes to the image, you can convert it to one of the read-only disk image formats.
Go to the Disk Utility app
on your Mac.If Disk Utility isn’t open, click
in the Dock, type Disk Utility in the Search field, then click .Choose Images > Convert, select the disk image file you want to convert, then click Choose.
Click the Image Format pop-up menu, then choose a new image format.
Read-only image (UDRO): A disk image that canʼt be changed after it is created. It’s fast to create and quick to open.
Read-only Compressed (ULFO): A read-only image that stores data in a compressed format.
Sparse Bundle Image (UDSB): A read/write image that grows with the data stored in it. The data is stored in multiple files. This structure is often used for Time Machine backups over a network.
RAW Image: An image that allows you to add, remove, or edit files in the disk image after itʼs created. The data is stored in the image file exactly as it is laid down in the virtual disk represented by the image.
Apple Sparse Image (ASIF): A modern sparse read/write image. The space it uses on your disk is proportional to the data it contains, making it efficient and general-purpose.
DVD/CD master: A disk format that can be used with third-party apps. It includes a copy of all sectors of the disk image, whether they’re used or not. When you use a master disk image to create other DVDs or CDs, all data is copied exactly.
If you want to change the encryption, click the Encryption pop-up menu, then choose an encryption type.
Enter a new name for the image in the Save As field, click Save, then click Done.