McCourt M
Department of Psychology, North Dakota State University, Fargo 58105-5075.
Vision Res. 1994 Jun;34(12):1609-17. doi: 10.1016/0042-6989(94)90118-x.
The magnitude of brightness variations within test fields of grating induction and phantom grating type displays was measured using a pointwise brightness matching paradigm. A range of test field luminances was sampled which encompassed those reported to give rise to both in-phase phantom and counterphase induced gratings. Results from four observers failed to reveal the existence of stationary "in phase" phantom gratings: at all test field luminances the spatial phase of brightness modulations was consistently opposite to that of the inducing grating. At low or high test field luminances, however, test field luminance matches to the bright or dark half-cycles of induced gratings approximate the luminances of the troughs or peaks of the dark or bright half-cycles of the inducing gratings, respectively. Thus, at low test field luminances the dark half-cycle of the inducing grating may appear to continue across the dark test field, and similarly, at high test field luminances the bright half-cycle may appear continuous with the bright test field. Previously misidentified as being "in-phase" with the inducing grating, the appearance of "phantoms" is suggested to arise due to the apparent brightness continuity of these induction-produced half-cycles of the induced grating across the test field.
使用逐点亮度匹配范式测量了光栅诱导和幻像光栅类型显示器测试场中的亮度变化幅度。对一系列测试场亮度进行了采样，其中包括据报道会产生同相幻像光栅和反相诱导光栅的亮度。四名观察者的结果未能揭示静止的“同相”幻像光栅的存在：在所有测试场亮度下，亮度调制的空间相位始终与诱导光栅的相位相反。然而，在低或高测试场亮度下，测试场亮度与诱导光栅亮或暗半周期的匹配分别近似于诱导光栅暗或亮半周期波谷或波峰的亮度。因此，在低测试场亮度下，诱导光栅的暗半周期可能看起来在暗测试场上延续，同样，在高测试场亮度下，亮半周期可能看起来与亮测试场连续。以前被错误地识别为与诱导光栅“同相”，“幻像”的出现被认为是由于诱导光栅这些感应产生的半周期在测试场上明显的亮度连续性。
