RMagick is a complete interface between the Ruby programming language and the ImageMagick and GraphicsMagick image processing libraries. For details on how to install and use and for more info about RMagik see the user's guide.

Working with RMagick is very easy. Here are some examples:

The simplest example: read an image and display it
require 'RMagick'

 include Magick

 im = ImageList.new("image1.jpg")

 im.display

 exit
In this example, the following actions are done:
- Require the RMagick.rb
- Include the Magick module
- Create a new ImageList containing only one image
- Display the the list of images

You can convert an image from one format to another easily with RMagick:
im = ImageList.new("image1.jpg")

im.write("image1.gif")
As simple as that. You can create annimated gif from a number of gif images:
im = ImageList.new("image1.gif", "image2.gif", "image3.gif")

im.write("annim.gif")
You can create image and add text:
# We create the background

logo = Magick::ImageList.new('logo:')

img = Magick::ImageList.new

img.new_image(200, 100, Magick::TextureFill.new(logo))

# We set some text properties

text = Magick::Draw.new

text.font_family = 'helvetica'

text.pointsize = 52

# We write the text and set its color

text.annotate(img, 0,0,2,2, "Must@p") {

	self.fill = 'darkred'

}
You can make thumbnails:
# We reduce the image to 20% of its size

im1 = Image.new "image1.gif"

im2 = im1.scale(0.20)

im2.write "small.gif"
You can rotate an image:
im1 = Image.new "image1.gif"

im2 = Im1.rotate(30); # 30 degrees
You can add a shadow to an image:
im1 = Image.new "image1.gif"

# x_offset=5, y_offset=5, sigma=4.0, opacity=1.0

im2 = Im1.shadow(5,5,4.0,1.0);
There are many effects that you can add to an image. See the manual.
I must stop here because there are many functions that you can apply to an image and I can't enumerate them All.

Conclusion:
With RMagick you have an easy to use and powerful tool to manipulate images. Try it your self.