RGB and CMYK Color Model in Digital Image Processing
A color model is a system for creating a full range of colors from a small set of primary colors.
There are two types of color models:
- Additive color model: Use light to display color.
- Subtractive color model: Used in printing inks.
RGB Color Model
The RGB color model is an additive color model. In this care red, green and blue light are added together in various combinations to reproduce a wide spectrum of colors.
The primary purpose of the RGB color model is for the display of images in electronic systems, such as on television screens and computer monitors and it's also used in digital photography.
Cathode Ray Tube, LCD, Plasma and LED displays, all utilize the RGB model.
In order to create a color with RGB, three colored light beams (one red, one green, and one blue) must be superimposed.
With no intensity, each of the three colors is perceived as black, while full intensity leads to a perception of seeing white.
Differing intensities produce the hue of a color, while the difference between the most and least intense of the colors makes the resulting color more or less saturated.
CMYK Color Model
The CMYK color model (four-color process) is a subtractive color model.
CMYK works by partially or completely masking colors on a white background.
The printed ink reduces the light that would otherwise be reflected. That's why this model is called subtractive because inks 'subtract' brightness from a white background from four colors: cyan, magenta, yellow, and black.
CMYK is able to produce the entire spectrum of visible colors due to the process of half-toning.
In this process, each color is assigned a saturation level and minuscule dots of each of the three colors are printed in tiny patterns.
This enables the human eye to perceive a specific color made from their combination. In order to improve print quality and reduce large-scale interference patterns, the screen for each color is set at a different angle.