RISE Images

There is another option to get copies of images from a course:

Publish the course for the web, go to contents > assets, and then pull the images from there. 

NOTE: Currently in Rise, when you upload an image, you can select the option to preserve its quality.

Before that option was implemented, to preserve quality, you had to add "_NOPROCESS_" to the end of the original image's file name before it was uploaded.

Unfortunately, there's no way (at least, not that I know of) to switch to the preserve-file-quality option for an image that's already been uploaded. So if you didn't use that setting, and you don't see "_NOPROCESS_" at the end of the file name, the quality won't be as good as the original when you publish the course.