Image sampling effects have been variously quantified as aliased signal, spatial signal, and spatial noise. However, a relationship between these characteristics and human object recognition has not been established in a coherent, mathematical form. We present a heuristic study that characterizes the performance degradation that is due to the spurious response of a sampled imaging system as an effective increase in system blur. A character recognition experiment was performed in which 20 observers responded to 3500 character pairs of blur and sample spacing. A baseline was created where the probability of character recognition was determined as a function of blur without sampling. The sampled characters were then compared with this baseline so that the effect of sampling on character recognition could be determined. Finally, an increase in blur was established as a function of spurious response, which describes the overall effect of sampling on observer character recognition.
© 1999 Optical Society of America
Original Manuscript: February 18, 1998
Revised Manuscript: October 22, 1998
Manuscript Accepted: January 27, 1999
Published: May 1, 1999
Ronald G. Driggers, Richard Vollmerhausen, and Barbara O’Kane, "Equivalent blur as a function of spurious response of a sampled imaging system: application to character recognition," J. Opt. Soc. Am. A 16, 1026-1033 (1999)