IMG (file format)
Encyclopedia
The IMG file format is one of the following files:
  1. A CD or DVD image file, essentially equivalent to an ISO file. On such a file, simply changing the extension from IMG to ISO can make it usable as the latter by most programs.
  2. An archive format
    Archive format
    An archive format is the file format of an archive file. The archive format is determined by the file archiver. Some archive formats are well-defined by their authors and have become conventions supported by multiple vendors and/or open-source communities....

     used for creating a disk image
    Disk image
    A disk image is a single file or storage device containing the complete contents and structure representing a data storage medium or device, such as a hard drive, tape drive, floppy disk, CD/DVD/BD, or USB flash drive, although an image of an optical disc may be referred to as an optical disc image...

     of floppy disks and HDDs. This allows for digital storage, transmission, and replication of floppy disks and HDDs. Files created using this format typically use the ".IMG" file extension. There are different, incompatible image formats which use the .IMG extension.
  3. A file in the Macintosh Disk Image format used by Aladdin Systems (now Allume Systems
    Allume Systems
    Allume Systems was a software developer, originally founded in 1988 by David Schargel and Jonathan Kahn in New York City as Aladdin Systems to develop, publish and distribute software for personal computers. Allume was incorporated in January 1989...

    ) ShrinkWrap
    Shrinkwrap
    Shrink wrap, also shrinkwrap or shrink film, is a material made up of polymer plastic film. When heat is applied it shrinks tightly over whatever it is covering. Heat can be applied with a hand held heat gun or the product and film can pass through a heat tunnel on a conveyor.-Composition:The...

     and Apple Disk Copy for Mac OS
    Mac OS
    Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...

     although they share the same file extension.
  4. The IMG file format, also known as GEM IMG, is an image file format used to store bitmap digital images on Graphical Environment Manager
    Graphical Environment Manager
    GEM was a windowing system created by Digital Research, Inc. for use with the CP/M operating system on the Intel 8088 and Motorola 68000 microprocessors...

    .
  5. A graphics image format used in various ways by many different graphics software packages.

IMG formats

The IMG file extension is used by files which are standardised raw dumps of a disk, and by files in various formats created by different imaging programs.
  • A raw dump
    Dump
    Dump generally refers to a place for disposal of domestic waste. See articles at midden and landfill.-Other uses:The word has other uses alone or in combination and may refer to:* Dump , a Unix program for backing up file systems...

     of the content of a disk is usually saved with the extension .IMG. This format is not compatible with the Disk Copy Fast
    Disk Copy Fast
    Disk Copy Fast is a file archiver software utility that creates disk images of floppy disks. It also refers to the file format used to encode the disk image files created...

      and DiskDupe format but is supported by multiple software vendors and conventions. It contains the same data as the IMA
    IMA (file format)
    The IMA file format is an archive format used for creating a disk image of floppy disks. This allows for digital storage, transmission, and replication of floppy disks. Files created using this format typically use the ".IMA" file extension.- Format details :...

     file format. In this case the image typically begins with a FAT boot sector, where the first byte is normally hexadecimal EB (code for a 8bit short jump, offset in the 2nd byte) with third byte 90 (code for a NOP), or rarely EA (code for a 16bit jump, offset in 2nd and 3rd byte). The file size will always be a multiple of the sector size — generally 512 bytes, but other sizes such as 128 and 1024 existed. More precisely the file size corresponds to Cylinders×Heads×(Sectors per track), e.g., 1440KB=80×2×18×512 for 80 cylinders (tracks) and 2 heads (sides) with 18 sectors per track.

  • Files with the .IMG extension files are created by MS-DOS tools such as HDCopy
    HDCopy
    HDCopy is a disk image application for floppy disks that runs in MS-DOS. It can copy a floppy on the fly, or by using archives with IMG file extension that store the content of the disk with a proprietary file format .It was written by Oliver Fromme and is distributed as...

     which store the contents of a disk in a usually compressed form, different for different imaging programs: the .IMG extension is not standardised for other than raw images, and .IMG files created by different programs are not necessarily compatible. The first few bytes of the file may identify the imaging program that created it; as the file is compressed its size depends upon the contents of the image.

Support and development

The raw IMG file format is currently supported by GNU
GNU Project
The GNU Project is a free software, mass collaboration project, announced on September 27, 1983, by Richard Stallman at MIT. It initiated GNU operating system development in January, 1984...

 RaWrite & RaWrite2, and RawWrite for Windows. It is utilized by Qemu
QEMU
QEMU is a processor emulator that relies on dynamic binary translation to achieve a reasonable speed while being easy to port on new host CPU architectures....

, VirtualBox
VirtualBox
Oracle VM VirtualBox is an x86 virtualization software package, originally created by software company Innotek GmbH, purchased by Sun Microsystems, and now developed by Oracle Corporation as part of its family of virtualization products...

 and WinImage
WinImage
WinImage is a disk imaging application for Microsoft Windows created by Gilles Vollant Software. Its features include creating, reading and editing disk images and also opening VMware and Microsoft Virtual PC hard disk images...

.

Nero Burning ROM
Nero Burning ROM
Nero Multimedia Suite is a popular software suite for Microsoft Windows by Nero AG . Version 10 of this product was released in April 2010.- Included products :The following applications are included in Nero 11 :Disc authoring...

 prior to 6.0 supported reading IMG file for creating bootable CD, but since then calls them IMA
IMA (file format)
The IMA file format is an archive format used for creating a disk image of floppy disks. This allows for digital storage, transmission, and replication of floppy disks. Files created using this format typically use the ".IMA" file extension.- Format details :...

.

Image files with the .IMG extension but not in raw image format are produced by several imaging programs, and are not necessarily compatible with each other, or with programs which handle raw images. There are programs which will convert between the image formats used by various programs, including raw format; one such is dsktrans from the the LibDsk suite of command-line tools for Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

, MS-DOS
MS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...

, and Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

.

Programs such as ImDisk and Virtual Floppy Drive can mount a raw image of a floppy disk to emulate a floppy drive under Windows.

Use

IMG files are used for:
  • Digital storage, transmission, and replication of floppy disks.
  • Mounting virtual floppy disk volumes.

External links

  • img to iso Convert IMG disk image to ISO disk image
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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