| Summary: | 碩士 === 國立臺灣大學 === 物理研究所 === 94 === Color can be seen everywhere. There are two main color specification systems. One is color appearance system, which describes color by its three quantities-- hue, saturation, and brightness. The other is color-mixed system, which divides color into trichromacy (red, green, and blue). We usually use color appearance system to describe color in our daily life. We measure reflecting spectrum of objects to find out the character of physics on color. Conclusions we made show below:
1.Understanding physical meaning of three quantities of color.
According to reflectional spectrum of pictures, we can measure hue by main wave length. Saturation can be measured by the difference of the average of spectral reflectance of the main wave length and the minimum of spectral reflectance. Brightness is determined by the intensity of reflectance of objects. Therefore, the total intensity of reflectance of objects can be gotten by the sum of RGB values.
2.Relationship between color of mixing lights and monochromatic light
After two monochromatic light are mixed in different proportion of color intensity, they can produce another color which is beyond wave length of components. It makes relation between intensity of component lights and color. Then we can infer intensity of original component lights from color of lights.
3.Analysis of colorful pictures in monitors.
Color from monitors belongs to RGB additive primaries. Although different spectral forms of trichromacy in CRT and LCD, we still can get the same color by different proportion of mixing colors. The third conclusion is the same as the second conclusion.
4.Guess the color distribution of single-slit diffraction pictures.
We can get the width of central bright stripe and ordinary bright stripe by the sum of RGB. In addition, we use concepts of main wave length to make a conclusion. Take the sun light as an example, yellow is the color of the first colorful stripe in single-slit diffraction. Saturation can be measured by the difference of the average of spectral reflecatance of the main wave length and the minimum of spectral reflectance. We can also guess the color distribution of pictures in other forms of complex lights.
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