Unit-4
RGB Color Model:-
Based on tristimulus theory of vision our eye perceives color through stimulate one
of three visual pigments in the cones of the retina.
These visual pigments have peak sensitivity at red, green and blue color.
So combining these three colors we can obtain wide range of color this concept is
used in RGB color model
As shown in figure this model is represented as unit cube. Origin represent black
color and vertex (1,1,1) is white.
Vertex of the cube on the axis represents primary color R, G, and B.
In XYZ color model any color intensity is obtained by addition of primary color.𝐶𝜆 =
𝑅𝑅 + 𝐺𝐺 + 𝐵𝐵
Where R, G, and B is amount of corresponding primary color
Since it is bounded in between unit cube it’s values is very in between 0 to 1 and
represented as triplets (R,G,B). For example magenta color is represented with
(1,0,1).
Shades of gray are represented along the main diagonal of cube from black to white
vertex.
For half way gray scale we use triplets (0.5,0.5,0.5).
HSL
HSV is a cylindrical color model that remaps the RGB primary colors into
dimensions that are easier for humans to understand. Like the Munsell Color
System, these dimensions are hue, saturation, and value.
Hue specifies the angle of the color on the RGB color circle. A 0° hue results in red,
120° results in green, and 240° results in blue.Saturation controls the amount of
Unit-4 1
Unit-4
RGB Color Model:-
Based on tristimulus theory of vision our eye perceives color through stimulate one
of three visual pigments in the cones of the retina.
These visual pigments have peak sensitivity at red, green and blue color.
So combining these three colors we can obtain wide range of color this concept is
used in RGB color model
As shown in figure this model is represented as unit cube. Origin represent black
color and vertex (1,1,1) is white.
Vertex of the cube on the axis represents primary color R, G, and B.
In XYZ color model any color intensity is obtained by addition of primary color.𝐶𝜆 =
𝑅𝑅 + 𝐺𝐺 + 𝐵𝐵
Where R, G, and B is amount of corresponding primary color
Since it is bounded in between unit cube it’s values is very in between 0 to 1 and
represented as triplets (R,G,B). For example magenta color is represented with
(1,0,1).
Shades of gray are represented along the main diagonal of cube from black to white
vertex.
For half way gray scale we use triplets (0.5,0.5,0.5).
HSL
HSV is a cylindrical color model that remaps the RGB primary colors into
dimensions that are easier for humans to understand. Like the Munsell Color
System, these dimensions are hue, saturation, and value.
Hue specifies the angle of the color on the RGB color circle. A 0° hue results in red,
120° results in green, and 240° results in blue.Saturation controls the amount of
Unit-4 1
