Most popular display color management and

Display color management and ICC profile

display is a computer output device, but for printing practitioners, it is an important window to adjust color, observe image and adjust levels. It is the main basis for judging image quality, and it is also the key to realize color "what you see is what you get". Therefore, only by accurately adjusting the display can we better complete the design of prepress image

the calibration of the display includes two parts: the basic setting of the display and the color calibration

1. basic setting of display

for Mac machine, open the display and sound options in the system folder control panel, and make the brightness and contrast buttons of the display in the middle normal position. If the display is used for a long time, the brightness value can be appropriately increased. In addition, set the resolution of the display to "800dpix600dpi/bhz or" 1024dpi x 768dpi, 75Hz ". At the same time, relevant parameters should be set

(1) gamma: the printing gamma value is generally set to 1.8. Gamma value represents the functional relationship between image output and input, which directly affects the level and depth of visual observation image. Ideally, the input and output of all devices should be linear, and the gradient curve is a 45 'slash. However, in actual production, the input and output of many devices are not linear, and the deviation is large in the middle tone. Therefore, according to the printing characteristics, gamma should choose 1.8

(2) white point: since the color temperature of sunlight is 6500k, in order to simulate the normal observation environment, the color temperature of 6500k is selected

(3) phosphors: screen fluorescence type, which should match the system display

(4) room parameters: ambient light brightness, optional medium. If it's too dark, choose lo, and you don't know the functional characteristics of the cast iron hydraulic universal testing machine? W (low); If it is too bright, choose high. For Windows operating system, set the resolution of the display to 800dpi x 600dpi, 75-z stroke 850mm "or" 1024dpi x 68dpi, 75/1z, and the number of color bits is greater than 24bit. Note that it is best to set the desktop color to gray to avoid the shadow of the desktop color on the image:

after installing Photoshop, the "adobegamma" setting option will appear in the "control panel", which can set the gamma value of the display

2. display color correction

the display color correction can be automatically completed by the software. The sample color data displayed on the screen can be taken into the software through the online color measuring equipment. The software will automatically correct the screen color according to these data, and can be manually corrected with the cooperation of the software. At present, there are several levels of display correction systems, some of which are only different. The display correction system

is software, while some require hardware (colorimeter or spectrophotometer) cooperation. The display calibration system can be divided into two categories, namely, external calibration system and internal calibration system. The former is divided into full software or human eye adjustment and colorimeter or spectrophotometer instrument adjustment. This adjustment system can not adjust the color of the display, but can realize the enhancement of fixed and control activities in a fixed segment, and obtain the ideal color by correcting the look cluster table (LUT table for short) on the computer display card. Table 1 shows the calibration systems of several displays

3. Generation of 1cc profile of display

taking Heidelberg scanning software newcolor7000 as an example, this paper introduces the production of ICC prof-e file of the display

(1) wipe the display clean, connect the colorimeter, and warm up for half an hour after startup

(2) start the newcolor 7000 software and open the viewopen ICC dialog box

(3) viewopen[cc will initialize the colorimeter.

(4) set the color temperature, brightness, contrast and gamma value of the display.

(5) place the probe of the colorimeter in the white area in the center of the display, and press the "start/stop,, button to correct the color. Viewopen has the characteristics of small size, light weight, high precision and convenient use. ICC will test the 32 color blocks displayed in the center of the display screen.

(6) Select the brightness of the working environment and press "start/stopviewopen ICC to generate the ICC profile of the display

(7) save the generated ICC profile file

(author/Li Yuxia)

information source/printing technology 2005, 10 (Publishing and commercial printing)