NextGEN gallery

I really like this plugin but I am having trouble getting the images to size properly. My client is uploading tons of images and they are all being uploaded full size. 3.5MB. This is eating up disk space in a hurry. Will NG reduce the file size before uploading so there is not as much disk space being used up?

Also, it creates sever different size variations of the same image. Is there a way to control that too?

Many thanks,
Houston