电子科妓女学光电科学与工程学院 SCHOOL OF OPTOELECTRONIC SCIENCE AND ENGINEERING OF UESTC 1.RGB Color Model TABLE 6.1 Number System Color Equivalents Valid values of Hex 00 33 66 99 CC FF each RGB Decimal 0 51 102 153 204 255 component in a ■Safe RGB safe color. colors:a subset b FIGURE 6.10 of RGB colors. (a)The 216 safe RGB colors. (b)All the grays in the 256-color RGB system (grays that are part of the safe color group are shown underlined). There are 216 colors common in most 000000 66666 aaaaaa operating FIGURE 6.11 The RGB safe-color cube. systems
1. RGB Color Model ◼ Safe RGB colors: a subset of RGB colors. There are 216 colors common in most operating systems
电子科线女学光电科学与工程学院 SCHOOL OF OPTOELECTRONIC SCIENCE AND ENGINEERING OF UESTC 2.CMY and CMYK Color Models CMY:Cyan/Magenta/Yellow Γ1 R M 1 G r 1 B CMYK:Cyan/Magenta/Yellow/Black
2. CMY and CMYK Color Models 1 1 1 C R M G Y B = − ◼ CMY: Cyan/Magenta/Yellow ◼ CMYK: Cyan/Magenta/Yellow/Black
电子科妓女学光电科学与工程学院 SCHOOL OF OPTOELECTRONIC SCIENCE AND ENGINEERING OF UESTC 3.The HSI Color Model RGB/CMY models are not good for human interpreting. HSI Color model Hue: Dominant color Saturaion:Relaive ri (invproC Color carrying information to amount of white light added) Intensity:Brightness
◼ RGB/CMY models are not good for human interpreting. ◼ HSI Color model Color carrying information 3. The HSI Color Model Hue: Dominant color Saturation: Relative purity (inversely proportional to amount of white light added) Intensity: Brightness
电子科妓女学光电科学与工程学院 SCHOOL OF OPTOELECTRONIC SCIENCE AND ENGINEERING OF UESTC 3.The HSI Color Model White White ab FIGURE 6.12 Conceptual relationships Magenta Magenta between the RGB Cyan Yellow Cyan Yellow and HSI color models. Blue Red Blue Red Green Green Black Black
3. The HSI Color Model
电子科妓女学光电科学与工程学院 SCHOOL OF OPTOELECTRONIC SCIENCE AND ENGINEERING OF UESTC 3.The HSI Color Model Green Yellow 1.A dot is the plane is White'、 Cyan Red an arbitrary color. Blue Magenta Green Yellow Green Yellow Green 2.Hue is an angle from a Cyan Red Cyan Yellow Cyan Red red axis. H Blue Magenta Blue Magenta Red Blue Magenta a 3.Saturation bcd is a distance FIGURE 6.13 Hue and saturation in the HSI color model.The dot is an arbitrary color point.The angle from the red axis gives the hue,and the length of the vector is the to the point saturation.The intensity of all colors in any of these planes is given by the position of the plane on the vertical intensity axis
1. A dot is the plane is an arbitrary color. 2. Hue is an angle from a red axis. 3. Saturation is a distance to the point. 3. The HSI Color Model