色彩知觉perceivingcolor-myweb.ppt

* * * * * Figure 7.24: The reflectance curve of a sweater (green curve) and the wavelengths reflected from the sweater when it is illuminated by daylight (white) and by tungsten light (gold). * * Figure 7.25: Adapting field for chromatic adaptation demonstration. * * * * * * Figure 7.28: This unevenly illuminated wall contains both reflectance edges and illumination edges. The perceptual system must distinguish between these two types of edges to accurately perceive the actual properties of the wall and other parts of the scene, as well. * * * * Figure 7.29: The pattern created by shadows on a surface is usually interpreted as a change in the pattern of illumination, not as a change in the material making up the surface. The fact that we see all of the bricks on this wall as made of the same material, despite the illumination changes, is an example of lightness constancy. * * * * * * * * * * * * * Figure 7.13a: Absorption spectrum for pigment 1, showing how to determine the number of molecules isomerized by 1,000 photons of 550- and 590-nm light. The number on the left axis is the percentage of light absorbed. The numbers indicated by the arrows on the right are this percentage multiplied by the intensity of each wavelength. The table shows the result as the number of pigment molecules isomerized by each wavelength. * * * * * * * * * * * * * * * * * * * * * * * 亮度恆常性 反射入眼的光度不同時，對於非色彩（achromatic）色（如黑、灰、白）的知覺仍然維持恆定 反射率比較重要—而非反射的光度 * 比率法則（ratio principle） 平面的知覺受其與周邊強度的比例所影響 加上對於陰影的詮釋 * * Fig. 7-28, p. 160 Reflectance edge Illumination edge 照明邊界 反射邊界 * * * * Fig. 7-29, p. 161 Meaningful shapes help define that it is a shadow and thus an illumination edge Perceptual Experiences are Creations of the Nervous System Physical energy in the environment does not have perceptual qualities. Light waves are not “colored.” Different nervous systems experience different perceptions. Honeybees perceive color at 350nm, which is outside human perception. We cannot tell what color the