Just to follow-up, I resized all of the images for my Windows platform. 41,814 files. It was originally 15.7 GB. With the Fotosizer application I reduced the size of all the images by 20% and reduced the quality of the images by 40% which reduced the total size of images to 4.25 GB. So, I saved about 10GB for that one platform. I think the image quality is still more than fine. Here are the before and after examples:
Before re-size and compression:
After re-size and compression: