GIMP (GNU Image Manipulation Program) is a freely distributed program for such tasks as

• photo retouching,
  
• image composition and
  
• image authoring.
  

It has many capabilities. It can be used as

• a simple paint program,
  
• an expert quality photo retouching program,
  
• an online batch processing system,
  
• a mass production image renderer,
  
• an image format converter, etc.

For more information and download go to... http://portableapps.com/apps/graphics_pictures/gimp_portable