CONTRAST SENSITIVITY UNDER DIFFERENT SURROUND LUMINANCE

摘要

The contrast sensitivity function (CSF) is central to describe spatial vision. Measurements ofcontrast sensitivity are fundamental to model human vision and to predict visual performance. In the Measurements, surround luminance is a crucial parameter affecting the contrast sensitivity. In the paper, we investigated how the luminance of office lighting surround to a visual target affected the measurement of contrast sensitivity to rectangular gratings. We examined six young, healthy subjects under three kinds of lightings with surround luminance of 183, 347, 510cd/m~(2) and the dark room condition. Measurements were carried out on a CRT monitor for 11 spatial frequencies at a viewing distance of 2m. Tested grating patterns on the screen were with two kinds of average luminance of 60 and 90cd/m~(2). Measurements results showed that observers were the most sensitive to gratings with average luminance of 60cd/m~(2) under the surround with the luminance of 347cd/m~(2) in three kinds of lightings condition, and when viewing the gratings with average luminance of 90cd/m~(2), contrast sensitivity was reduced with surround luminance increasing, and all contrast sensitivity under the lighting viewing condition was much smaller than one under the dark room viewing condition. But possible reasons for the difference in the effect of surround need be discussed further. So a goal of our experiment was to obtain their relations and effects of surround luminance on contrast threshold measured with a CRT monitor.