When you upload images in the cart the thumbnail image is resized according to the pixel dimensions you specify in the buynow settings and the large image is uploaded as is. If the need arises, you can manually create thumbnails and/or resize your thumbnail or large images individually or on the entire directory at once.
The following are steps to create/resize all your thumbnails at once:
- Download the Image Resizer PowerToy for your O.S. (there are different flavors for XP, Vista, 7, etc)
- Copy all of the images to your thumbnails directory
- Do a Control-A (Select All)
- Right-click one of the images
- Select "Resize Images"
- Make them the size that you want
That's how to resize imported images without going through uploading each one and having it run the thumbnail routine.