Summary: Discriminability measures for predicting
readability of text on textured backgrounds
Lauren F. V. Scharff, Alyson L. Hill
Stephen F. Austin State University, Department of Psychology, Nacogdoches, Texas, 75962
lscharff@sfasu.edu and alyson_hill@hotmail.com
and Albert J. Ahumada Jr.
NASA Ames Research Center, Moffett Field, CA 94035­1000
aahumada@mail.arc.nasa.gov
Abstract: Several discriminability measures were examined for their
ability to predict reading search times for three levels of text contrast and a
range of backgrounds (plain, a periodic texture, and four spatial­frequency­
filtered textures created from the periodic texture). Search times indicate
that these background variations only affect readability when the text
contrast is low, and that spatial frequency content of the background affects
readability. These results were not well predicted by the single variables of
text contrast (Spearman rank correlation = ­0.64) and background RMS
contrast (0.08), although a global masking index and a spatial­frequency­
selective masking index led to better predictions (­0.84 and ­0.81,
respectively).
©2000 Optical Society of America

Source: Ahumada Jr., Al - Vision Science and Technology Group, Human Factors Research and Technology Division, NASA Ames Research Center

Collections: Engineering