Piggy is capable of building thumbnail all by using plain Ruby and FXRuby but you might
want to increase the quality of the result by switching options and make Piggy use
one of the following tools:
- RMagick
- Nconvert (the batch processing application of the great image converter XNview)

*** RMagick

Homepage: http://rubyforge.org/projects/rmagick/

Installation on Windows:

This is, what worked for me:
1. Download binary distribution.
2. Unpack e. g. into something like F:\transfer
3. Open console window on the RMagick-Folder

Now the gem installation and postinstall:
>>
F:\transfer\RMAGIC~1.3-W>gem install RMagick-win32-1.9.2-mswin32.gem
Attempting local installation of 'RMagick-win32-1.9.2-mswin32.gem'
Successfully installed RMagick-win32, version 1.9.2

F:\transfer\RMAGIC~1.3-W>postinstall
RMagick 1.9.2 win32 Post Installation (see enclosed README for license informati
on)
detecting available fonts, writing to config/type-windows.xml...Warning: Ignored
 file c:/winnt/fonts/micross.ttf, exception occurred.
Warning: Ignored file c:/winnt/fonts/MICN__DB.TTF, exception occurred.
[...]
Warning: Ignored file c:/winnt/fonts/21205___.TTF, exception occurred.
ok.
setting MAGICK_CONFIGURE_PATH to 'E:/ruby/lib/ruby/gems/1.8/gems/RMagick-win32-1
.9.2-mswin32/config'.
setting is only for current user.
Copying 5 dlls to E:/ruby/bin...done.
all done.
<<

Installation on Linux is most easy if you run a Debian flavoured Linux: Simply
download and install the Debian package.


*** NConvert

Homepage: http://perso.wanadoo.fr/pierre.g/xnview/en_nconvert.html

Installation on Windows:

Copy nconvert.exe into a directory of your choice which is part of the PATH variable, e. g
into C:\ruby\bin.

For Linux there are RPM packages availiable.