有源CIELAB颜色空间的建立与应用

Establishment and Application of TS/P CIELAB Color Space

建立有源CIELAB颜色空间,使用颜色感知色相角h、感知饱和度C*和感知亮度L*,观察RGB颜色和油墨颜色的特性。研究表明,利用有源CIELAB颜色空间,可以看到以256阶调RGB三原色表述的颜色,在绿-青-蓝色相角区间会缺少对可见光足够的表现力;在饱和度和亮度较低区域,颜色会缺失很多。如果增加新的青原色,可以有效扩大颜色空间;增加原色的阶调级数在10倍以上,可以有效增加颜色饱和度和阶调的平滑度。使用简约12位RGB颜色,可以将颜色数有效控制在7560万种以内,仅比8位RGB颜色数增加4倍多。油墨颜色不应再延续使用网点面积百分率整数表示,阶调级数应达到256以上。

In this paper, the TS/P （tricolor spectrum or some pigment） CIELAB color space was established, and color perceptive hue angle h and perceptive saturation C＊ and perceptive brightness L＊ were used to observe the characteristic of RGB color and printing ink color. It can be found that RGB tricolor can display color with 256 tones in TS/P CIELAB color space. It caused the scarcity for expressive force of visible light in green-cyan-blue color hue angle area and the scarcity for color in the area where saturation and brightness has lower level. To add a cyan color as fourth color as tricolor can extend availably color space. To expand RGB tricolor tone to 2560 upwards can amend the color saturation and smoothness of brightness. To use Reduce-12 bit （R-12b） RGB color can control color number not exceed 75.6 million, which is 4 times more than 8-bit RGB only. Ink color shouldn’t use percent integer of dot area to display in the future and the level of tone should be exceed 256 at least.