az image --help Manage custom virtual machine images.

[addaxnasom]

Group
    az image : Manage custom virtual machine images.

Subgroups:
    template [Preview] : Manage and build image builder templates.

Commands:
    create             : Create a custom Virtual Machine Image from managed disks or snapshots.
    delete             : Deletes an Image.
    list               : List custom VM images.
    show               : Gets an image.
    update             : Update custom VM images.