Modelling Character Legibility

Introduction The process by which humans distinguish visually between letters of the alphabet is a matter of considerable theoretical and practical interest. On the theoretical side, it is a classical problem in psychology, and has served as a test case for numerous theories of feature analysis and pattern recognition. On the practical side, it is relevant to the effective design of any textual display. Furthermore, principles discovered in the study of letter recognition may generalize to the perception of other types of displayed information. In the psychological literature, a number of theories of letter discrimination have been proposed. These may be roughly divided into those that are feature-based, and those that are image-based. The former predict letter similarity based on the sharing of particular features, such as vertical lines, concave right curves, etc 1 . A defect of these models is that they do not specify the process by which the letter image is trans