A short taxonomy of image quality models is proposed. Although the taxonomy includes medical and security image quality, its primary focus is commercial imaging, where the image quality judgment by the user is often cast as a “beauty contest” selection from images produced by competing products. By taking a broad view of “image quality models,” it seems possible to arrange them into categories based on how they are applied in practice. This taxonomy illustrates and clarifies an array image of image quality models applicable to many practical applications.