Plugin Galaxy is a collection of 20 photography and graphic effects plug-ins for Adobe Photoshop. Plugin Galaxy is also compatible with many non-Adobe photo editors. The selection of filters range from variations on traditional effects such as "Bluuur" and "Noiseee," to the unusual, such as "Zoom" (which zooms in on portions of a photo) and "Coolorize" (which provides a unique set of color adjustment tools). I'll start out with a look at the Coolorize filter, and then take a quick glance at the Zoom filter as well.

#1 The Plugin Galaxy Coolorize filter. All Photos 2005, Anthony L. Celeste, All Rights Reserved

The Plugin Galaxy Coolorize Filter
The Plugin Galaxy filters can be found in "The Plugin Site" filter submenu. The Coolorize filter's interface is shown in #1. There are a total of 10 types of color adjustments available from the drop-down box in the upper right:
RGB Intensify, Color Tuning, and YUV Intensify: These options all offer control over color fine-tuning.
Magic Invert: This is a variation on the traditional Photoshop negative effect, it creates a more colorful negative with smoother color blending.
Twilight: This option intensifies sunset/sunrise colors in a photo.
Fade: Somewhat similar to a mild Vignette filter, in which the edges of the photo begin to fade to black.
B/W Limiter and Greyscaler: B/W Limiter creates an interesting effect by converting some of the color in your image to gray scale. Greyscaler is a simple RGB to gray scale converter. The Coolorize B/W Limiter can be very useful. However, if it's complete gray scale conversion that you want, consider using Photoshop's gray scale conversion instead of Greyscaler, since Greyscaler does not perform dithering on the gray scale image.
Cartoon Look: Reduces color count, creating the look of a vector drawing.
RGB Saturation: Saturates the Red, Green, and Blue color channels. This can be a convenient tool, since Photoshop only allows you to saturate one channel at a time. Using Coolorize, you can saturate each channel at different settings, and watch a live preview of the result, all at the same time.

All of the sliders in the Coolorize filter work on a scale of 0 (no effect) to 255 (strongest effect). Clicking the reset button in the upper right corner will take you to random slider settings for the effect selected in the drop-down box.

#2 An autumn landscape before using the Coolorize filter.

Creating A Limited Gray Scale With The Coolorize B/W Limiter
I thought it would be interesting to try the Coolorize filter's B/W Limiter option on an image with a wide variety of colors, such as an autumn landscape. Image #2 shows the landscape before any adjustments.

#3 An autumn landscape after using the Coolorize filter. I wanted to create a less colorful, more melancholy look for this photo. I set the first set of Red and Green sliders to 35, and the first Blue slider to 128. I set the second set of Red and Green sliders to 200, and the second Blue slider to 128. This caused the colorful mid tones that use the Red and/or Green color channels to be desaturated, while the darker and brighter reds and greens remained in the image. Since both of the Blue sliders were set to 128, there were no changes made to the Blue color channel. There's also an interesting Color Theory effect at play here: bright yellow is now a fairly dominant color in this image, because in the RGB color space, bright yellow is a combination of bright red and bright green.