Noorlander C, Heuts M G, Koenderink J J
J Opt Soc Am. 1980 Sep;70(9):1116-21. doi: 10.1364/josa.70.001116.
The effect of the target size on the detecton of luminance and chromaticity flicker and gratings was studied. Discrimination ellipses in a luminance-chromaticity plane were determined with square test areas subtending from 1/4 degree to 1 degree. Pure luminance modulation thresholds and pure chromaticity modualtion thresholds were obtained from square targets subtending from 1/16 degree to 2 degree. Square-wave stimuli were presented on a color television monitor; the mean color of the screen was yellow, the average retinal illuminance was 350 td. The main effect of enlarging the field size is that the threshold for any luminance-chromaticity combination decreases monotonically except when spatial frequencies are high. The summation area for detecting a fine bar pattern is at least 8 x 8 periods; the integration area for detecting flicker is more than 1 degree x 1 degree. This holds for any luminance-chromaticity mixture. For a fixed spatial or a fixed temporal frequency the change in sensitivity sometimes depends strongly on the ratio of luminance modulation to chromaticity modulation. The main conclusion of this study is that if a target is predominantly yellow the target size has similar influence on the sensitivity to both luminance and chromaticity contrast.
研究了目标大小对亮度、色度闪烁及光栅检测的影响。采用张角从1/4度到1度的方形测试区域，确定了亮度 - 色度平面中的辨别椭圆。从张角为1/16度到2度的方形目标获取了纯亮度调制阈值和纯色度调制阈值。方波刺激呈现在彩色电视监视器上；屏幕的平均颜色为黄色，平均视网膜照度为350td。扩大视场大小的主要影响是，除了空间频率较高时，任何亮度 - 色度组合的阈值都会单调降低。检测细条图案的总和区域至少为8×8个周期；检测闪烁的积分区域大于1度×1度。这适用于任何亮度 - 色度混合情况。对于固定的空间频率或固定的时间频率，灵敏度的变化有时强烈取决于亮度调制与色度调制的比率。本研究的主要结论是，如果目标主要为黄色，则目标大小对亮度和色度对比度的敏感度具有相似的影响。
