After you download and uncompress the .zip or tar.gz files, before you run the http://127.0.0.1/ez to install the website.
1) Create the file of "/ez/settings/override/image.ini.append.php", insert the code as below:
<?php /* #?ini charset="utf-8"?
[ImageConverterSettings]
ImageConverters[]
ImageConverters[]=GD
ImageConverters[]=ImageMagick
[GD]
Name=GD
IsEnabled=true
Handler=eZImageGDFactory
[ImageMagick]
IsEnabled=true
ExecutablePath=/usr/local/bin
Executable=convert
*/ ?>
[ImageConverterSettings]
ImageConverters[]
ImageConverters[]=GD
ImageConverters[]=ImageMagick
[GD]
Name=GD
IsEnabled=true
Handler=eZImageGDFactory
[ImageMagick]
IsEnabled=true
ExecutablePath=/usr/local/bin
Executable=convert
*/ ?>
Then when you install the website, you can ignore the step to have to install the ImageMagick