How to Install and Use Plug-Ins in Pixelmator

Extend This Powerful App's Functionality

A woman working at a computer using software to analyze qualitative data.
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Pixelmator is a powerful and increasingly popular photo editor for use on Apple Mac OS X. It lacks the outright power of Adobe Photoshop, the industry standard photo-editing tool, but it has many similarities and is available for a small fraction of the price.

It also can't match the power and feature set of GIMP, the free, popular and established open source photo editor. While Pixelmator has no price advantage over GIMP, it offers a much more stylish and user-friendly interface to help smooth your workflow.

Plug-ins Add Functionality

Using Pixelmator may feel like a bit of a compromise next to Photoshop, but Pixelmator fills that gap with plug-ins. Most Photoshop and GIMP users already are familiar with the process of extending these apps by downloading and installing plug-ins, many of which are offered for free. Pixelmator users, however, may be less aware that they, too, can take advantage of plug-ins to add new functionality to the popular photo editor.

This is perhaps because they aren't exclusively Pixelmator plug-ins, but plug-ins that are installed at a system level to extend the graphics capabilities of the operating system itself. Additionally, a great range isn't available, and finding these plug-ins can take some searching.

Pixelmator is compatible with two types of plug-ins: Core Image units and Quartz Composer compositions.

Installing Core Image Units

You can find a few useful Core Image units available for free download on the Belight Community website.

For instance, the BC_BlackAndWhite plug-in brings a more powerful Channel Mixer to Pixelmator. In particular, it allows you to convert color digital photos to black and white on a per color channel basis, which opens up the possibility of much more creative mono conversions. You also can apply a color tint to your image, in a similar way you apply color filters in Photoshop.

Here's how to install a Core Image unit:

  1. After downloading a suitable Core Image unit, unzip it.
  2. Open a Finder window and navigate to the root of your Mac. Note that this isn't your Home folder; it should be the hard drive first listed under Devices at the top of the side bar.
  3. Navigate to Library > Graphics > Image Units. Place your Core Image unit into that folder.
  4. If Pixelmator is already running, close it, then relaunch.
  5. Look in the Filter menu of Pixelmator for the plug-in you installed. (You might need to check the sub menus, too.) For example, if you installed the BC_BlackAndWhite plug-in, you'll find it under the Color sub menu.

Installing Quartz Composer Compositions

Quartz Composer compositions are another type of plug-in that Pixelmator recognizes. You'll find a larger selection of these than Core Image units on the Belight Community website. One complication of using these compositions, however, is the fact that Pixelmator is compatible only with compositions created by Quartz Composer 3.

If you're not able to establish which version of Quartz Composer was used to create a plug-in, try installing it to see if it is recognized by Pixelmator.

  1. Open a Finder window and navigate to the root of your Mac.
  1. Go to User Library > Compositions. Place your downloaded plug-ins in this folder.
  2. If Pixelmator is running, close it, then reopen.
  3. If the plug-in is compatible with Pixelmator, you will find it under Filter > Quartz Composer. Be sure to check existing sub menus, too.

The option of installing plug-ins into Pixelmator offers a great deal of promise, though the selection is a little limited at the time of this writing. As Pixelmator develops into a more powerful photo editor, however, a larger user base will stimulate greater production of more exciting Core Image units and Quartz Composer compositions.