A site with a great number of products may need to bulk-upload images, rather than uploading them one by one through the admin site. 

Procedure 

The best way to do this is by FTP'ing the images, and using ImageFilenameOverride. When you create the products (whether through the admin site or the bulk import), specify the filename (with extension) that you want the software to use for that product's images in the ImageFilenameOverride field. Then upload your images to the right folders, and the images will be picked up automatically. 

For example, if a product has Giantsheep.jpg in the ImageFilenameOverride field, the software will look for giantsheep.jpg in the /images/products/icon|medium|large folders.