ImageMagick, invoked from the command line as magick, is a free and open-source[3] cross-platform software suite for displaying, creating, converting, modifying, and editingraster images. ImageMagick was created by John Cristy in 1987, it can read and write over 200 image file formats. It is widely used in open-source applications.
History
ImageMagick was created in 1987 by John Cristy when working at DuPont, to convert 24-bit images (16 million colors) to 8-bit images (256 colors), so they could be displayed on most screens at the time. It was freely released in 1990 when DuPont agreed to transfer copyright to ImageMagick Studio LLC, still currently the project maintainer organization.[5][6][7]
In May 2016, it was reported that ImageMagick had a vulnerability through which an attacker can execute arbitrary code on servers that use the application to edit user-uploaded images.[8] Security researchers at Cloudflare observed use of the vulnerability in active hacking attempts.[9] The security flaw was due to ImageMagick calling backend tools without first properly checking to ensure path and file names are free of improper shell commands.[10] The vulnerability did not affect ImageMagick distributions that included a properly configured security policy.[citation needed]
A number of programs, such as Drupal, MediaWiki, phpBB, and vBulletin, can use ImageMagick to create image thumbnails if installed. ImageMagick is also used by other programs, such as LyX, for converting images.
ImageMagick has a fully integrated Perlbinding called PerlMagick,[11] as well as many others: G2F (Ada), MagickCore (C), MagickWand (C), ChMagick (Ch), ImageMagickObject (COM+), Magick++ (C++), JMagick (Java), L-Magick (Lisp), NMagick (Neko/Haxe), MagickNet (.NET), PascalMagick (Pascal), MagickWand for PHP (PHP), IMagick (PHP), PythonMagick (Python), RMagick (Ruby), and TclMagick (Tcl/Tk).
File format conversion
One of the basic and thoroughly-implemented features of ImageMagick is its ability to efficiently and accurately convert images between different file formats (it uses the command magick to achieve this).
Color quantization
The number of colors in an image can be reduced to an arbitrary number by weighing the most prominent color values present among the pixels of the image.
A related capability is the posterization artistic effect, which also reduces the number of colors represented in an image. The difference between this and standard color quantization is that while in standard quantization the final palette is selected based upon a weighting of the prominence of existing colors in the image, posterization creates a palette of colors smoothly distributed across the spectrum represented in the image. Whereas with standard color quantization all of the final color values are ones that were in the original image, the color values in a posterized image may not have been present in the original image but are in between the original color values.
Dithering
A fine control is provided for the dithering that occurs during color and shading alterations, including the ability to generate halftone dithering.
Liquid rescaling
In 2008, support for liquid rescaling was added.[12] This feature allows, for example, rescaling 4:3 images into 16:9 images without distorting the image.
Artistic effects
ImageMagick includes a variety of filters and features intended to create artistic effects:
Color management: accurate color management with color profiles or in lieu of – built-in gamma compression or expansion as demanded by the colorspace.
High-dynamic-range images: accurately represent the wide range of intensity levels found in real scenes ranging from the brightest direct sunlight to the deepest darkest shadows.
Encipher or decipher an image: convert ordinary images into unintelligible gibberish and back again.
Virtual pixel support: convenient access to pixels outside the image region.
Large image support: read, process, or write mega-, giga-, or tera-pixel image sizes.
Threads of execution support: ImageMagick is thread safe and most internal algorithms execute in parallel to take advantage of speed-ups offered by multi-core processor chips.
Heterogeneous distributed processing: certain algorithms are OpenCL-enabled to take advantage of speed-ups offered by executing in concert across heterogeneous platforms consisting of CPUs, GPUs, and other processors.
Distributed pixel cache: offload intermediate pixel storage to one or more remote servers.
GraphicsMagick is a fork of ImageMagick 5.5.2 made in 2002, emphasizing the cross-release stability of the programming API and command-line options. GraphicsMagick emerged as a result of irreconcilable differences in the developers' group.[15]
^"History". ImageMagick. Archived from the original on March 14, 2018. Retrieved March 18, 2018. Dr. Pensak had to convince upper management at DuPont. ... Either way, ImageMagick would not be available today without DuPont transferring the copyright to ImageMagick Studio LLC. ImageMagick was posted to Usenet's comp.archives group on August 1, 1990.
ImageMagick Security Policy – ImageMagick Security Policy – best practices strongly encourages you to configure a security policy that suits your local environment
IM Examples – Examples of CLI Usage – provides many small examples demonstrating its vast range of capabilities
Fred's ImageMagick Scripts – provides a plethora of shell scripts using ImageMagick to do more complex tasks
