The definition and origin of color management

First, the definition of color management

Color is a kind of visual nerve stimulation, and its production is due to the response of the optic nerve to light. Without light or optic nerves, there is no color (don't think light is equal to color).
The following figure illustrates the response of humans and some animals to light:

In 1931, the CIE (Commission Internationale de I`Eclairage) published a CIExyY color space map that represents the range of human-visible colors (see Figure 2). Since then, CIE published new color models in 1964, namely CIE Lab and CIE Luv, which have the same color range as CIE xyY, but differ in shape and expression. CIE Lab is mostly used for color management systems.

Second, the origin of color management

1, the traditional color management - prepress -

Although the Colour Electronic Prepress Systems (CEPS) in the 1970s and 1980s had functions such as editing graphics, typesetting, and color control, each prepress system was incompatible with each other and expressed differently in color. If a file is output in different prepress systems, it is likely to produce different results. As shown in Figure 3, the old-style management method is relatively complicated. For example, six unique color conversion programs are required.

--print--

Printers mainly control the color according to the white point, ink color and dot gain. If there is no proper management method, each production will be different. (Note: The color management system is mainly computer software. It uses a color model and decides how to translate colors.)

2. Modern color management

-- Prepress and Printing Industry --

From the middle of the 1980s to the present, computers and software have developed rapidly. Digital output plates and digital printing have emerged. Figure 4: Modern color management method (open design), this method makes color management more efficient.

In addition to mechanical and composite circuits, the color output of these devices is greatly affected by their inherent color management. The initial color management of new products is incompatible with each other. It is precisely because these new digital products are gradually becoming popular that developers and users begin to understand the importance of compatibility.

In 1993, the International Color Consortium (ICC), a group of eight computer and electronic image developers, was established to solve the problem of color management compatibility among new products. ICC decided that color management should be based on computer operating systems. , And use "ICC Profile" (color description file) for color conversion, any input or output device supports this format, then they can make accurate color conversion between. As shown in Figure 4, with the ICC-supported operating system as the color management center, each device requires only one ICC Profile (color profile file), and the system can simply manage colors. Today ICC has joined more than fifty famous companies as members, and the ICC Profile also has a lot of new product support. It can be said that it has become an industry standard.


Figure 5: No color management (cannot predict results) Figure 6: Use color management (predictable results)