This is the official website of the GNU Image Manipulation Program (GIMP).

GIMP is a cross-platform image editor available for GNU/Linux, OS X, Windows and more operating systems. It is free software, you can change its source code and distribute your changes.

Whether you are a graphic designer, photographer, illustrator, or scientist, GIMP provides you with sophisticated tools to get your job done. You can further enhance your productivity with GIMP thanks to many customization options and 3rd party plugins.



gimp -i -b '(simple-unsharp-mask "foo.png" 5.0 0.5 0)' -b '(gimp-quit 0)'

More details, see here: GIMP Batch Mode



A complete, cross-platform solution to record, convert and stream audio and video.

An ImageJ plugin is available for using FFMPEG in ImageJ. Add its update sites (see the listing here)

For handling video files in ImageJ/Fiji, see also here.

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Dithering is a type of half tone thresholding where greyscale (or RGB channel) intensity is converted into a local density of binary pixels. This is ideal for rendering images in devices with a binary output such as printers (greyscale) or with a small number of colours (colour dithering). The following methods have been implemented (there are several more):

  • Floyd-Steinberg
  • Atkinson
  • Jarvis-Judice-Ninke
  • Stucki
  • Bayer_2x2
  • Bayer_4x4
  • Bayer_8x8
  • Clustered_4x4
  • Random

Here is a good text explaining various dithering algorithm.

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