I have a bunch of images such as this one that are completely pixelated, and I my friend wants to make large prints to hang in her house. How can I smooth these out so they will not appear pixelated? If I apply anti aliasing, would that be enough? If so, what kind of anti aliasing? Is there a good way to convert these to vector graphics? What level of image quality do people typically need in order for a large print to look good?
To be clear, these images are various resolutions including 800x600 and 960x720. Every pixel takes on one of exactly three colors. There has been no smoothing or averaging in these pictures yet.