"Trope" comes from a Greek word meaning "turn." In the rhetorical sense, a trope refers to a "turn" in the way that words are being used to communicate something more than--or different from--a literal or straightforward message. Tropes are part of "deep structure" meanings and include such rhetorical devices as allegories, allusions, euphemisms,…

M. Singh and B. L. Anderson proposed a perceptual theory of achromatic transparency in which the perceived transmittance of a perceived transparent filter is determined by the ratio of the Michelson contrast seen in the region of transparency to that of the background seen directly. Subsequently, B. L. Anderson, M. Singh, and J. Meng proposed that…

All of the data reported in Robilotto, Khang, and Zaidi (2002) Robilotto and Zaidi (2004), and Singh and Anderson (2002) are consistent with Robilotto and Zaidi's theory that perceived transparency (or opacity) is determined by the perceived contrast of the filter region. Kasrai and Kingdom's (2001) results also appear largely consistent with the…