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. The number of colors in an image can be reduced to an arbitrary number and this is done by weighing the most prominent color values present among the pixels of the image.Ī related capability is the posterization artistic effect, which also reduces the number of colors represented in an image. 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 convert to achieve this).
ImageMagick has a fully integrated Perl binding called PerlMagick, 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), or TclMagick (Tcl/TK). ImageMagick is also used by other programs, such as LyX, for converting images. The program uses magic numbers to identify image file formats.Ī number of programs, such as Drupal, MediaWiki, phpBB, and vBulletin, can use ImageMagick to create image thumbnails if installed. ImageMagick does not have a robust graphical user interface to edit images as do Adobe Photoshop and GIMP, but does include – for Unix-like operating systems – a basic native X Window GUI (called IMDisplay) for rendering and manipulating images and API libraries for many programming languages. The software mainly consists of a number of command-line interface utilities for manipulating images. The vulnerability did not affect ImageMagick distributions that included a properly configured security policy. 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.
Security experts including CloudFlare researchers observed actual use of the vulnerability in active hacking attempts. 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. It was freely released in 1990 when DuPont agreed to transfer copyright to ImageMagick Studio LLC, still currently the project maintainer organization. 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.
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