Multiple-image Network Graphics (MNG) is a graphics file format, published in 2001, for
animated
Animation is a method by which still figures are manipulated to appear as moving images. In traditional animation, images are drawn or painted by hand on transparent celluloid sheets to be photographed and exhibited on film. Today, most ani ...
images. Its specification is publicly documented and there are
free software
Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, n ...
reference implementations available.
MNG is closely related to the PNG image format. When PNG development started in early 1995, developers decided not to incorporate support for
animation
Animation is a method by which still figures are manipulated to appear as moving images. In traditional animation, images are drawn or painted by hand on transparent celluloid sheets to be photographed and exhibited on film. Today, most ani ...
, because the majority of the PNG developers felt that overloading a single file type with both still and animation features is a bad design, both for users (who have no simple way of determining to which class a given image file belongs) and for web servers (which should use a MIME type starting with image/ for stills and video/ for animations—GIF notwithstanding). However, work soon started on MNG as an animation-supporting version of PNG. Version 1.0 of the MNG specification was released on 31 January 2001.
File support
Support
Gwenview
Gwenview is an image viewer for Unix-like systems (including Linux) and is released as part of the KDE Applications bundle. The current maintainer is Aurélien Gâteau. The word "Gwen" means "white" in the Breton language and is commonly used as ...
has native MNG support.
GIMP
GIMP ( ; GNU Image Manipulation Program) is a free and open-source raster graphics editor used for image manipulation (retouching) and image editing, free-form drawing, transcoding between different image file formats, and more specialized ...
can export images as MNG files.
Imagemagick
ImageMagick, invoked from the command line as magick, is a free and open-source cross-platform software suite for displaying, creating, converting, modifying, and editing raster images. Created in 1987 by John Cristy, it can read and write ov ...
can create a MNG file from a series of PNG files. With the MNG plugin,
Irfanview
IrfanView () is an image viewer, editor, organiser and converter program for Microsoft Windows. It can also play video and audio files, and has some image creation and painting capabilities. IrfanView is free for non-commercial use; commercial u ...
can read a MNG file. If
MPlayer
MPlayer is a free and open-source media player software application. It is available for Linux, OS X and Microsoft Windows. Versions for OS/2, Syllable, AmigaOS, MorphOS and AROS Research Operating System are also available. A port for DOS using ...
is linked against libmng, it and all its graphical front-ends like Gnome MPlayer can display MNG files.
Mozilla
Mozilla (stylized as moz://a) is a free software community founded in 1998 by members of Netscape. The Mozilla community uses, develops, spreads and supports Mozilla products, thereby promoting exclusively free software and open standards, ...
browsers and
Netscape
Netscape Communications Corporation (originally Mosaic Communications Corporation) was an American independent computer services company with headquarters in Mountain View, California and then Dulles, Virginia. Its Netscape web browser was on ...
6.0, 6.01 and 7.0 included native support for MNG until the code was removed in 2003 due to code size and little actual usage, causing complaints on the Mozilla development site. Mozilla later added support for APNG as a simpler alternative. Similarly, early versions of the
Konqueror
Konqueror is a free and open-source web browser and file manager that provides web access and file-viewer functionality for file systems (such as local files, files on a remote FTP server and files in a disk image). It forms a core part of t ...
browser included MNG support but it was later dropped. MNG support was never included in
Google Chrome
Google Chrome is a cross-platform web browser developed by Google. It was first released in 2008 for Microsoft Windows, built with free software components from Apple WebKit and Mozilla Firefox. Versions were later released for Linux, macOS, ...
,
Internet Explorer
Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated IE or MSIE) is a series of graphical web browsers developed by Microsoft which was used in the Windows line of operating systems (in ...
,
Opera
Opera is a form of theatre in which music is a fundamental component and dramatic roles are taken by singers. Such a "work" (the literal translation of the Italian word "opera") is typically a collaboration between a composer and a libr ...
, or
Safari
A safari (; ) is an overland journey to observe wild animals, especially in eastern or southern Africa. The so-called "Big Five" game animals of Africa – lion, leopard, rhinoceros, elephant, and Cape buffalo – particularly form an impor ...
.
Server support
Web servers generally don't come pre-configured to support MNG files.
The MNG developers had hoped that MNG would replace GIF for animated images on the
World Wide Web
The World Wide Web (WWW), commonly known as the Web, is an information system enabling documents and other web resources to be accessed over the Internet.
Documents and downloadable media are made available to the network through web ...
, just as PNG had done for still images. However, with the expiration of LZW patents and existence of alternative file formats such as APNG, Flash and
SVG
Scalable Vector Graphics (SVG) is an XML-based vector image format for defining two-dimensional graphics, having support for interactivity and animation. The SVG specification is an open standard developed by the World Wide Web Consortium s ...
, combined with lack of MNG-supporting viewers and services, web usage was far less than expected.
Technical details
The structure of MNG files is essentially the same as that of PNG files, differing only in the slightly different signature (8A 4D 4E 47 0D 0A 1A 0A in
hexadecimal
In mathematics and computing, the hexadecimal (also base-16 or simply hex) numeral system is a positional numeral system that represents numbers using a radix (base) of 16. Unlike the decimal system representing numbers using 10 symbols, he ...
, where 4D 4E 47 is ASCII for "MNG" – see Portable Network Graphics: File header) and the use of a much greater variety of chunks to support all the animation features that it provides. Images to be used in the animation are stored in the MNG file as encapsulated PNG or JNG images.
Two versions of MNG of reduced complexity are also defined: MNG-LC (low complexity) and MNG-VLC (very low complexity). These allow applications to include some level of MNG support without having to implement the entire MNG specification, just as the
SVG
Scalable Vector Graphics (SVG) is an XML-based vector image format for defining two-dimensional graphics, having support for interactivity and animation. The SVG specification is an open standard developed by the World Wide Web Consortium s ...
standard offers the "SVG Basic" and "SVG Tiny" subsets.
MNG does not have a registered
MIME
Multipurpose Internet Mail Extensions (MIME) is an Internet standard that extends the format of email messages to support text in character sets other than ASCII, as well as attachments of audio, video, images, and application programs. Message ...
media type, but video/x-mng or image/x-mng can be used.
MNG animations may be included in
HTML
The HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaS ...
pages using the or tag.
MNG can either be lossy or lossless, depending whether the frames are encoded in PNG (lossless) or JNG (lossy).
Alternatives
The most common alternatives are
Animated GIF
The Graphics Interchange Format (GIF; or , see pronunciation) is a bitmap image format that was developed by a team at the online services provider CompuServe led by American computer scientist Steve Wilhite and released on 15 June 1987. ...
and – up until its deprecation in 2017 –
Adobe Flash
Adobe Flash (formerly Macromedia Flash and FutureSplash) is a multimedia software platform used for production of animations, rich web applications, desktop applications, mobile apps, mobile games, and embedded web browser video players. Flash ...
, with the relative newcomer
video alternative to GIF
The Graphics Interchange Format (GIF; or , see pronunciation) is a bitmap image format that was developed by a team at the online services provider CompuServe led by American computer scientist Steve Wilhite and released on 15 June 1987. ...
recently gaining momentum. Animated GIF images are restricted to 256 colors and are used in simple scenarios but are supported in all major web browsers.
In web pages, it is possible to create pseudo-animations by writing
JavaScript
JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of websites use JavaScript on the client side for webpage behavior, of ...
code that loads still PNG or JPEG images of each frame and displays them one by one for a specified time interval. Apart from requiring the user to have JavaScript support and choose not to disable it, this method can be CPU- and bandwidth-intensive for pages with more than one image, large images, or high framerates, and does not allow the animation to be saved in one image file or posted on image-based sites such as
flickr
Flickr ( ; ) is an American image hosting and video hosting service, as well as an online community, founded in Canada and headquartered in the United States. It was created by Ludicorp in 2004 and was a popular way for amateur and profession ...
or
imageboards
An imageboard is a type of Internet forum that focuses on the posting of images, often alongside text and discussion. The first imageboards were created in Japan as an extension of the textboard concept. These sites later inspired the creation of ...
.
Most web browsers support APNG, a non-standard extension to PNG for simple GIF-like animations. Another alternative is
SVG
Scalable Vector Graphics (SVG) is an XML-based vector image format for defining two-dimensional graphics, having support for interactivity and animation. The SVG specification is an open standard developed by the World Wide Web Consortium s ...
JPEG
JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and imag ...
JavaScript
JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of websites use JavaScript on the client side for webpage behavior, of ...
to flip between images.
Internet Explorer
Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated IE or MSIE) is a series of graphical web browsers developed by Microsoft which was used in the Windows line of operating systems (in ...
CSS 3
Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language such as HTML or XML (including XML dialects such as SVG, MathML or XHTML). CSS is a cornerstone techno ...
features, notably CSS Animation, which now has some level of support in most major web browsers. CSS Sprites (providing several images as tiles in a single large image file) can be used as animations by varying which part of the large image is visible using CSS Animation or JavaScript.