Grayscale and resolution trade-offs in photographic image quality

This paper summarizes the results of a visual psychophysical investigation of the relationship between two important printer parameters: addressability (expressed in terms of dots per inch or DPI) and grayscale capability (expressed in terms of the number of graylevels per pixel). The photographic image quality of print output increases with both the printer DPI and the number of graylevels per pixel. The experiments described in this paper address the following questions: At what point is there no longer a perceptual advantage of DPI or graylevels, and how do these two parameters tradeoff?