G’MIC: FANTASTIC FILTERS FOR BREWING IMAGES By Debi Dalio, Edited by Sandra Livingston
Do you enjoy using filters in GIMP, but wish there were more options available? Have you ever wanted to define your own sequences of artistic effects that you could use on more than one image without having to go through each step manually every time? Would you like to be able to experiment with various filters on multiple image layers and have the output go to another layer or another file so that your original layers remain unaffected? If so, read on to learn about a new filter plugin called G’MIC.
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WHAT IS G’MIC?
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G’MIC, which stands for GREYC’s Magic Image Converter, is an open source image processing framework which allows you to convert, manipulate, filter, and visualize generic multidimensional, multi-spectral image datasets. Its basis is the CImg library, around which is wrapped the G’MIC scripting language. On top of this are several user interfaces: a command-line tool called gmic, a plugin for GIMP called gmic_gimp, and a graphical user interface for the webcam video stream manipulation program ZArt. The set of predefined filters can be extended with custom-written G’MIC scripts. There is even an online version of G’MIC at https://gmicol.greyc.fr/ that lets you upload your own image to which you can apply a subset of filters and then download the result.
WHAT DOES IT DO?
G’MIC gives you access to a plethora of predefined filters, all in one convenient package. When you run it in GIMP, it opens
its own window within which you can select a filter, adjust the filter’s controls, and see the filter’s output on your selected image before you push the button to generate the output. For anyone used to using other open source filter tools, here’s how G’MIC compares. • G’MIC is similar to ImageMagick and GraphicsMagick in that they are all based on low-level libraries and provide commandline tools for image manipulation, but G’MIC is more versatile in the types of images it works with; plus, it provides a highly portable scripting language. • G’MIC is similar to Fx Foundry in that both provide a scripting language. The major benefit that G’MIC has over Fx Foundry is that G’MIC’s preview window lets you see the effects of a filter as you adjust the controls. If you use Fx Foundry, you’ll be interested to know that G’MIC has an API that allows it to be called from an Fx Foundry Scheme script. • G’MIC is similar to MathMap in that both can be used to