The two most significant parameters affecting degradations of bilevel images are the point spread function (PSF) width and the binarization threshold. Each pair of these values will affect an image differently. However, several combinations of these parameters will affect images in a similar fashion. This paper looks at two aspects of image degradation: the displacement of an edge, which determines stroke width, and the erosion of a corner, which affects crispness. The relationship between the PSF width and the binarization threshold and these two effects will be described. Sample characters, first with similar edge displacement and second with similar corner erosion, will show the effect of estimating the broader degradation versus the exact system parameters. Methods of estimating these degradations will also be briefly discussed.