I offer a way to determine properties of mathematical functions through a new visualization method that takes advantage of human perception of images. Since the digitization of images turns images into arrays of numbers, one can apply mathematical functions to images on a pixel-by-pixel basis. Thanks to the pattern recognition skills of humans, the form of the transformed images can give ready insight into the behavior of those mathematical functions. I explain the method and give some examples here, with a particular focus on number theoretic functions.