Image quality is, ultimately, a measure of preference, a very subjective phenomenon. This tutorial will explore the quantitative analysis of image quality of digital color printing systems, using established scientific principles where possible and ad hoc empiricism where necessary, to find the relationships between physical measurements, human perception, and preference. The basic properties of the human visual system will be discussed, in particular the sensitivity to color and spatial frequency, which are critical to determining human perception of image quality defects. Application of such a representation of human vision to development of objective metrics for selected image quality defects will be illustrated. A system for classifying overall image quality in terms of a set of image quality attributes will be presented and analyzed, and emerging standards on perceptual image quality of printed images, based on this system, will be reviewed.