An Etymological Dictionary of Astronomy and Astrophysics

In an → image, the degree of distinction between areas with different → brightness levels;
in other words, the → ratio of the brightness between light and → dark areas.

Etymology (EN): From Fr. contraster, from It. contrastare “stand out against,” from V.L. *contrastare “to withstand,” from L. → contra- “against” + stare “to stand,” (cf. Pers. istâdan “to stand,” O.Pers./Av. sta- “to stand, stand still; set,” Skt. sthâ- “to stand,” Gk. histemi “put, place, weigh,” PIE base *sta- “to stand”).

Etymology (PE): Pâdsâni, from pâd- “agianst,” → contra- + sân “manner, semblance,” variant sun, Mid.Pers. sân “manner, kind,” Sogdian šôné “career” + -i noun suffix.