PREREQUISITES.md

Prerequisites

This file describes some prerequisites that need to be in place to make the web server fully functional.

Image Upload Resizing

In order to make full use of the mini_magick gem, the underlying ImageMagick library and binaries needs to be compiled.

The following instructions are specific to CentOS and Mac OS X systems.

Installing JPEG and PNG libraries

In order for ImageMagick to be able to handle JPEGs, the jpeg development libraries need to be installed first.

On CentOS:

$ [sudo] yum install libjpeg libjpeg-devel libpng libpng-devel

On Mac OS X:

Download and install the prebuilt JPG and PNG DMG here: http://ethan.tira-thompson.com/Mac_OS_X_Ports.html

Alternatively, you can compile them from source yourself. Mac libjpeg and libpng can be found here: http://www.libpng.org/pub/png/libpng.html, http://www.ijg.org/files/

Installing ImageMagick

Installing ImageMagick from source: http://www.imagemagick.org/script/install-source.php

$ cd ~/code/source
$ curl http://www.imagemagick.org/download/ImageMagick.tar.gz | tar xvz
$ cd ImageMagick-*
$ ./configure

After .configure you should see a line that includes jpeg and png:
DELEGATES       = mpeg jng jpeg png xml zlib

$ make
$ sudo make install

Verifying ImageMagick installation

Type the following to verify that the installation:

$ identify --version

Version: ImageMagick 6.8.9-7 Q16 x86_64 2014-09-09 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2014 ImageMagick Studio LLC
Features: DPC OpenMP
Delegates: jng jpeg png xml zlib

To check that PNG and JPEG support were successfully enabled, run the following command:

$ identify -list format

The list should include JPEG and PNG