Hayes A
Department of Psychology, University of Western Australia, Nedlands.
Perception. 1988;17(4):429-36. doi: 10.1068/p170429.
Unlike most multitone images, two-tone images such as print, geometric figures, and line drawings are as easy to interpret in photographic negative as in positive form. However, images derived from a multitone original in which intensity values are quantised to two levels are not. Bi-level quantised images, distinct from most other two-tone images, are shown to contain picture related components in their low spatial frequencies. Since it is the low-spatial-frequency components alone of negative images that present difficulties for vision, it is proposed that images which are as easy to interpret in negative as in positive form are those which are readily identified using only their high spatial frequencies.
与大多数多色调图像不同，双色图像（如印刷品、几何图形和线条画）在负片形式下与正片形式下一样易于解读。然而，从强度值被量化为两个级别的多色调原图派生而来的图像并非如此。与大多数其他双色图像不同，双级量化图像在其低空间频率中显示包含与图像相关的成分。由于负片图像仅其低空间频率成分给视觉带来困难，因此有人提出，在负片形式下与正片形式下一样易于解读的图像是那些仅使用其高空间频率就能轻松识别的图像。
