Apple Media Images

Choose where to keep your photos and videos

• Apple Media Hk

A sparse disk image is an automatically expanding disk image. In other words, you can create a 50 gigabyte sparse disk image, yet only put 5 megs inside it. The disk image will only take up five megs of space on your harddisk, but will be capable of storing up to 50 gigs of data should you choose to add it. Phiewer - The standard media viewer for Mac.-Phiewer is the easiest and fastest way to view your images, videos and even audio files. It's folder based so you can just browse your media in one window without any extra clicking an.

1. Fortunately, many formats are ideal for moving uncompressed or minimally compressed video files between applications, including Apple ProRes, Uncompressed 8- and 10-bit 4:2:2, DVCPRO50, and so on. Some codecs support an alpha channel, which defines areas of transparency in the clip.
2. Subject to the terms of this Marketing Agreement, Apple grants You a limited, non-exclusive, non-transferable, royalty-free, worldwide license to use the App Store badge, the App Store icon, and certain product images provided to You by Apple under this Marketing Agreement for Apple-branded products running iOS, watchOS, tvOS, or macOS (or any.
3. Apple Newsroom is the source for news about Apple. Read press releases, get updates, watch video and download images.

Make your photos and videos available on all of your devices with iCloud Photos. Or store them locally only on your Mac or PC.

iCloud Photos

iCloud Photos keeps your photos and videos safe, up to date and available automatically on all of your Apple devices, on iCloud.com, and even your PC. iCloud Photos always uploads and stores your original, full-resolution photos. You can keep full-resolution originals on each of your devices, or save space with device-optimised versions instead. Either way, you can download your originals whenever you need them. Any organisational changes or edits you make are always kept up to date across all of your devices.

The photos and videos that you keep in iCloud Photos use your iCloud storage. Before you turn on iCloud Photos, make sure that you have enough space in iCloud to store your entire collection. You can see how much space you need and then upgrade your storage plan if necessary.

Import to your Mac

You can use the Photos app to import photos from your iPhone, iPad or iPod touch to your Mac.

1. Connect your iPhone, iPad or iPod touch to your Mac with a USB cable.
2. Open the Photos app.
3. The Photos app shows an Import screen with all the photos and videos that are on your connected device. If the Import screen doesn't automatically appear, click the device's name in the Photos sidebar.
4. If asked, unlock your iOS device using your passcode. If you see a prompt on your iOS device asking you to Trust This Computer, tap Trust to continue.
5. Either select the photos you want to import and click Import Selected, or click Import All New Photos.
   
6. Wait for the process to finish, then disconnect your device from your Mac.

Learn what to do if you can't import photos from your iPhone, iPad or iPod touch to your computer.

Import to your PC

You can import photos to your PC by connecting your device to your computer and using the Windows Photos app:

1. Make sure that you have the latest version of iTunes on your PC. Importing photos to your PC requires iTunes 12.5.1 or later.
2. Connect your iPhone, iPad or iPod touch to your PC with a USB cable.
3. If asked, unlock your iOS device using your passcode.
4. If you see a prompt on your iOS device asking you to Trust This Computer, tap Trust or Allow to continue.

Then, visit Microsoft's website to learn how to import photos to the Windows Photos app in Windows 10.

If you have iCloud Photos turned on, you need to download the original, full-resolution versions of your photos to your iPhone before you import to your PC. Find out how.

When you import videos from your iOS device to your PC, some might be rotated incorrectly in the Windows Photos app. You can add these videos to iTunes to play them in the correct orientation.

Learn what to do if you can't import photos from your iPhone, iPad or iPod touch to your computer.

Learn more

• Use Time Machine to back up all of your files, including your photos and videos, to an external hard drive.
• Import photos and video from storage media, like a hard disk or SD card, to Photos for macOS.
• Use a scanner and Image Capture to import photos that were taken with a film camera.
• Import your images directly to a folder on your Mac with Image Capture.

Apple Disk Image is a disk image format commonly used by the macOS operating system. When opened, an Apple Disk Image is mounted as a volume within the Macintosh Finder.

An Apple Disk Image can be structured according to one of several proprietary disk image formats, including the Universal Disk Image Format (UDIF) from Mac OS X and the New Disk Image Format (NDIF) from Mac OS 9. An Apple disk image file's name usually has '.dmg' as its extension.

Features[edit]

Apple Disk Image files are published with a MIME type of application/x-apple-diskimage.

Different file systems can be contained inside these disk images, and there is also support for creating hybrid optical media images that contain multiple file systems.^[1] Some of the file systems supported include Hierarchical File System (HFS), HFS Plus, File Allocation Table (FAT), ISO9660 and Universal Disk Format (UDF).^[1][2]

Apple Disk Images can be created using utilities bundled with Mac OS X, specifically Disk Copy in Mac OS X v10.2 and earlier and Disk Utility in Mac OS X v10.3 and later. These utilities can also use Apple disk image files as images for burning CDs and DVDs. Disk image files may also be managed via the command line interface using the hdiutil utility.^[3]

In Mac OS X v10.2.3, Apple introduced Compressed Disk Images^[4] and Internet-Enabled Disk Images for use with the Apple utility Disk Copy, which was later integrated into Disk Utility in 10.3. The Disk Copy application had the ability to display a multilingual software license agreement before mounting a disk image. The image will not be mounted unless the user indicates agreement with the license.^[5]

An Apple Disk Image allows secure password protection as well as file compression, and hence serves both security and file distribution functions; such a disk image is most commonly used to distribute software over the Internet.

History[edit]

Apple originally created its disk image formats because the resource fork used by Mac applications could not easily be transferred over mixed networks such as those that make up the Internet. Even as the use of resource forks declined with Mac OS X, disk images remained the standard software distribution format. Disk images allow the distributor to control the Finder's presentation of the window, which is commonly used to instruct the user to copy the application to the correct folder.

How to unlock a used apple watch. A previous version of the format, intended only for floppy disk images, is usually referred to as 'Disk Copy 4.2' format, after the version of the Disk Copy utility that was used to handle these images.^[1] A similar format that supported compression of floppy disk images is called DART.^[1][6]

New Disk Image Format (NDIF) was the previous default disk image format in Mac OS 9,^[1] and disk images with this format generally have a .img (not to be confused with raw .img disk image files) or .smi file extension. Files with the .smi extension are actually applications that mount an embedded disk image, thus a 'Self Mounting Image', intended only for Mac OS 9 and earlier.^[7][2]

Universal Disk Image Format (UDIF) is the native disk image format for Mac OS X. Disk images in this format typically have a .dmg extension.^[1]

File format[edit]

Apple has not released any documentation on the format, but attempts to reverse engineer parts of the format have been successful. The encrypted layer was reverse engineered in an implementation called VileFault (a spoonerism of FileVault).^[8]

Apple disk image files are essentially raw disk images (i.e. contain block data) with some added metadata, optionally with one or two layers applied that provide compression and encryption. In hdiutil, these layers are called CUDIFEncoding and CEncryptedEncoding.^[1]

UDIF supports ADC (an old proprietary compression format by Apple), zlib, bzip2 (as of Mac OS X v10.4), and LZFSE (as of Mac OS X v10.11)^[9] compression internally.

Metadata[edit]

The UDIF metadata is found at the end of the disk image following the data. This trailer can be described using the following C structure.^[10] All values are big-endian (PowerPC byte ordering)

The XML plist contains a blkx (blocks) key, with information about how the preceding data fork is allocated. The main data is stored in a base64 block, using tables identified by the magic 'mish'. This 'mish' structure contains a table about blocks of data and the position and lengths of each 'chunk' (usually only one chunk, but compression will create more).^[10] The data and resource fork information is probably inherited from NDIF.

Encryption[edit]

The encryption layer comes in two versions. Version 1 has a trailer at the end of the file, while version 2 (default since OS X 10.5) puts it at the beginning. Whether the encryption is a layer outside of or inside of the blkx metadata (UDIF) is unclear from reverse engineered documentation, but judging from the vfcrack demonstration it's probably outside.^[8]

Utilities[edit]

There are few options available to extract files or mount the proprietary Apple Disk Image format. Some cross-platform conversion utilities are:

• dmg2img was originally written in Perl; however, the Perl version is no longer maintained, and the project was rewritten in C. It extracts the raw disk image from a DMG, without handling the file system inside. UDIF ADC-compressed images (UDCO) have been supported since version 1.5.^[11]
• DMGEXtractor is written in Java with GUI, and it supports more advanced features of dmg including AES-128 encrypted images but not UDCO images.^[12]
• The Sleuth Kit. Handles the DMG format, HFS+, and APFS.

Most dmg files are unencrypted. Because the dmg metadata is found in the end, a program not understanding dmg files can nevertheless read it as if it was a normal disk image, as long as there is support for the file system inside. Tools with this sort of capacity include:

• Cross-platform: 7-zip (HFS/HFS+), PeaZip (HFS/HFS+).
• Windows: UltraISO, IsoBuster, MacDrive (HFS/HFS+).^[13]
• Unix-like: cdrecord and mount (e.g. mount -o loop,ro -t hfsplus imagefile.dmg /mnt/mountpoint).^[14][15]

Tools with specific dmg support include:

• Windows:
  • Transmac can handle both UDIF dmgs and sparsebundles, as well as HFS/HFS+ and APFS. It is unknown whether it handles encryption.^[16] It can be used to create bootable macOS installers under Windows.^[17]
  • A free Apple DMG Disk Image Viewer also exists, but it is unknown how much what it actually supports.^[18]
• Unix-like:
  • darling-dmg is a FUSE module enabling easy DMG file mounting on Linux. It supports UDIF and HFS/HFS+.^[19]

See also[edit]

References[edit]

1. ^ ^abcdefg'hdiutil(1) Mac OS X Manual Page'. Archived from the original on 2016-05-14. Retrieved 2016-05-14.
2. ^ ^ab'Mac OS X: Using Disk Copy disk image files'. Archived from the original on 2013-12-19. Retrieved 2013-04-25.
3. ^hdiutil(1) – Darwin and macOS General Commands Manual
4. ^'Re: Some apps refuse to launch in 10.2.8! (OT, but very important)'. Archived from the original on 2014-01-17.
5. ^'Guides'. Apple. Archived from the original on 2009-03-06. Retrieved 2010-10-27.
6. ^'DART 1.5.3: Version Change History'. Archived from the original on 2013-12-19. Retrieved 2013-04-25.
7. ^'Software Downloads: Formats and Common Error Messages'. Archived from the original on 2010-12-24. Retrieved 2009-05-06.
8. ^ ^ab'VileFault'. 2006-12-29. Archived from the original on 2007-01-09. Retrieved 2010-10-27.
9. ^Michael Tsai (2015-10-07). 'LZFSE Disk Images in El Capitan'. Archived from the original on 2017-04-09. Retrieved 2017-04-09.
10. ^ ^ab'Demystifying the DMG File Format'. Archived from the original on 2013-03-17.
11. ^'dmg2img'. Archived from the original on 29 November 2010. Retrieved 2010-10-27.
12. ^'DMGExtractor'. Archived from the original on 2011-01-02. Retrieved 2011-01-03.
13. ^MacDrive Features / Boot Camp / System Requirements /. 'MacDrive Home page'. Mediafour. Archived from the original on 4 October 2010. Retrieved 2010-10-27.
14. ^'How To Convert DMG To ISO in Windows, Linux & Mac'. Archived from the original on 2010-03-07.
15. ^'Convert DMG To ISO using PowerISO'. Archived from the original on 2009-05-02. Retrieved 2009-02-15.
16. ^'About TransMac for Windows'. www.acutesystems.com.
17. ^'Convert'. www.winytips.com. winytips. Retrieved 5 May 2020.
18. ^Olivia Dehaviland (2015-03-03). 'Apple DMG Disk Image Viewer'. DataForensics.org. Archived from the original on 2015-04-02. Retrieved 2015-03-10.
19. ^'darling-dmg'. darling-dmg. Retrieved 29 March 2015.

External links[edit]

• Apple Developer Connection A Quick Look at PackageMaker and Installer
• O'Reilly Mac DevCenter Tip 16-5. Create a Disk Image from a Directory in the Terminal

Apple Media Hk