Rszr - fast image resizer for Ruby

Rszr is an image resizer for Ruby based on the Imlib2 library. It is faster and consumes less memory than MiniMagick, rmagick and GD2.

Installation

In your Gemfile:

gem 'rszr'

Imlib2

Rszr requires the Imlib2 library to do the heavy lifting.

OS X

Using homebrew:

brew install imlib2

Linux

Using your favourite package manager:

yum install imlib2 imlib2-devel

apt-get install libimlib2 libimlib2-dev

Usage

# bounding box 400x300
image = Rszr::Image.load('image.jpg')
image.resize(400, 300)

# save it
image.save('resized.jpg')

# save it as PNG
image.save('resized.png')

# auto height
image.resize(400, :auto)

# auto width
image.resize(:auto, 300)

# scale factor
image.resize(0.5)

# crop
image.crop(200, 200, 100, 100)

# rotate three times 90 deg clockwise
image.turn!(3)

# rotate one time 90 deg counterclockwise
image.turn!(-1)

# initialize copy
image.dup

# save memory, do not duplicate instance
image.resize!(400, :auto)

# image info
image.width => 400
image.height => 300
image.dimensions => [400, 300]
image.format => "jpeg"

Thread safety

As of version 0.4.0, Rszr is thread safe through the Ruby GIL. Use of any previous versions in a threaded environment is discouraged.

Speed

Resizing an 1500x997 JPEG image to 800x532, 100 times:

Library	Time
MiniMagick	12.9 s
GD2	7.5 s
Rszr	2.8 s