About

This repository contains the ruby library for easy interaction with MozJPEG compressor, an improved JPEG encoder (based on cjpeg).

Binaries of MozJPEG 3.0 for Mac OS X (64bit), Linux (64bit) and Windows are included in this gem.

This gem was successfully tested on the following systems: (test for binaries included in the source)

Mac OS X 10.10 - ruby 2.2.2 (PNG + JPEG)
Linux CentOS 6 - ruby 2.2.2 (JPEG only)
Windows XP - ruby 2.0.0p645 (JPEG only)

Please report other systems that work, any problems or questions opening an issue on GitHub.

Installation

Add this line to your application's Gemfile:

gem 'mozjpeg'

And then execute:

$ bundle

Or install it yourself as:

$ gem install mozjpeg

Usage

# check system support
Mozjpeg.supported? # true

# ask for location of (bundled) MozJPEG binary for current platform (Mac, Linux, Win)
Mozjpeg.cjpeg_path
# => /path/to/gems/bundled/cjpeg
# raises error if not supported

# compress JPEG file (accepts instances of File)
large_image = File.new('large.jpeg')
tiny_image = File.new('tiny.jpeg')

Mozjpeg.compress large_image, tiny_image

# to pass command line arguments to MozJPEG:
Mozjpeg.compress large_image, tiny_image, arguments: '-quality 70 -quant-table 2 -notrellis')

Paperclip

This gem was made to be used with the paperclip-mozjpeg gem, which adds file processor to compress JPEG images uploaded using the paperclip gem.

License

This gem is licensed under the MIT license.

MozJPEG license

The included JPEG fixture photo for tests is licenced under Creative Commons - CC0.

Contributing