Your camera has four picture quality settings:
High, Fine, Normal and Basic.
This reflects the amount of compression that is used on .jpg photos.
Do a test and take a 640 x 480 photo at each setting and see what kind of results you get.
Here is a link that describes the situation with sample photos:
Taking pictures to use on a website....my Sony CD pictures taken in 640x 480 image size look good on the computer, e mail well and look 4x6in photos look good. (Low Resolution) Using my new Nikon 5400 with same low resolution the same photos have a banding effect, a jagged edge effect. Telephone wires look broken up. A Nikon photo with 76k looks worse than a Sony CD with 64K. What is happening here? What don't I know. Strictly an amateur. Bill