As we all know, a typical image replication system includes multiple input and output devices (scanners, monitors, printers, etc.), and each device has its own way of expressing and restoring color, that is, color depends on the device . This is why a scanned photo image will show different colors on the display, on the proof sheet or on the printed manuscript. In response to this problem, many software developers at home and abroad have invested in the development of color management systems (CMS). The purpose is to manage the color of the entire copy process of the image to ensure that the appearance of the color of the same image from input to display and output is as consistent as possible. Photoshop is an image processing software developed by Adobe, and it is also a complete color management system. At present, this system is valued by people in the industry in color image processing. In the process of continuous software upgrades, color management functions have also been greatly improved. The following is a detailed discussion of Photoshop7's color management process and how to properly set the parameters of the software. 1. Calibration and characterization of the display In order to make the colors seen on the screen as close as possible to the colors of the output proofs, the display must be corrected first. Any color workflow starts with the calibration and characterization of the display. The purpose of calibration is to obtain the best image display environment in order to facilitate the editing of images. The purpose of characterization is to obtain the ICC profile of the monitor, which Photoshop can use to optimize the display of the monitor. Windows users can calibrate and characterize the monitor by running the Adobe Gamma utility. Mac OS users can achieve this through the ColorSync system or the Adobe Gamma utility. Here mainly discusses the monitor calibration and characterization under Windows system. 1. Follow the instructions in the introduction and select the "Step by Step (Wizard)" method. Second, Photoshop color settings After the monitor is calibrated, you can set the color of Photoshop. Enter "Edit → Color Settings", you can open the color settings dialog window, 70% of the color management is done here. Figure 2 shows the "Color Settings" window in Photoshop 7's default state. The dialogue window consists of 6 parts. These are "Settings", "Workspace", "Color Management Scheme", "Conversion Options", "Advanced Control" and "Description". If the "Advanced Mode" check box is not activated, there are no "Conversion Options" and "Advanced Control" sections. When the mouse moves to each section, there will be a short description of this section in the "Description" section at the bottom. 1. Settings in the "Settings" section The default option of "Settings" is "Web Graphics Default Settings", and different settings can be made according to the purpose of use and the area where it is located. If you want to simulate the printing press standard, choose "US Prepress Default Setting" or "European Prepress Default Setting" or "Japan Prepress Default Setting". If you don't want Photoshop to modify the color, choose "Color Management Off", but it is best not to This item (as shown in Figure 3). 2. Settings in the "Workspace" section First look at the RGB working space (as shown in Figure 4), we should choose "Adobe RGB (1998)" as the working color gamut of RGB images. The advantage is that the color gamut is moderate in size, which is larger than the general color gamut of CMYK printing. Therefore, when the printed color is displayed on the screen, there is usually no overflow, and it has been widely accepted as a standard before printing. "SRGB" is mainly used as the working color gamut of network image design. "ColorMatch" is generally the choice of Mac users, while "AppleRGB" is mainly the choice of network image design in the Mac system. The four working color gamuts are device-independent. If you want to set the workspace by yourself (not listed in the list), you need to select the "Custom RGB" option, set the parameters in the pop-up window and click "OK". The second is the CMYK working space, we can choose the "Load CMYK" option, according to the printing process of each image, select the corresponding ICC Profile file. If users are accustomed to using the CMYK settings from previous versions of Photoshop, they can choose the "Photoshop 5 Default CMYK" or "Photoshop 4 Default CMYK" option. If the image is only used for output on inkjet printers such as Epson and HP, the setting of this item is irrelevant, because the printer supports the RGB color space instead of the CMYK color space. Third, in the gray workspace, we should set accordingly according to the purpose of the grayscale image. For example, the grayscale image for printing can be set according to the percentage of dot correction (Dot Gain) required in the printing process (such as Dot Gain 10%, Dot Gain 15%, Dot Gain 20%, etc.). The user can also select the "customized dot correction" option and set the Dot Gain value according to their needs. Fourth, the setting of the spot color working space is similar to the setting of the gray working space, and will not be repeated here. 3. Settings in the "Color Management Scheme" section This part was added by Photoshop 6, and has not changed in Photoshop 7. As shown in Figure 5, each color space management scheme has the same 3 options. Depending on the purpose of the image output, selecting the "Off", "Keep Embedded Profile", and "Convert" options in the color management scheme will have completely different effects. Option "Off"-If the opened image has no embedded profile, the image will be edited in the currently defined workspace, and the profile will not be embedded when the image is stored; if the embedded profile of the image is consistent with the current color settings, The characteristic file of the image will be retained and stored with the image; if the characteristic file embedded in the image is inconsistent with the current color settings, the characteristic file of the original image will be deleted. This option is equivalent to eliminating the color management function. Option "Keep embedded profile" —The processing of images without embedded profiles is exactly the same as the option "Off"; if the profile embedded in the image is inconsistent with the current color settings, the image is still as described in the embedded profile The color is displayed on the monitor, and the current color setting has no effect on this image. Option "Convert"-If the characteristic file embedded in the image is inconsistent with the current color setting, the characteristic file is converted to the current color setting. 4. Settings in the "Conversion Options" and "Advanced Control" sections The "Engine" in the "Conversion Options" section requires the user to select a different CMM (Color Management Module). Generally, Adobe (ACE) is better. The "intent" can be selected from the four options listed (ie, relative colorimetric, absolute colorimetric, perceptible, and saturation), and it is generally better to select "perceptible" in prepress processing. The "Use black point compensation" check box should not be checked, and the "Use dithering" check box can be checked, which will help improve the quality of the outlets. The settings in the "Advanced Control" section only need to maintain Photoshop's default settings (as shown in Figure 6). When all the parameters are set, click "OK" to save the settings. Three, soft proofing Soft proofing is to use the display as a proofing device for proofing. In order to achieve accurate soft proofing in Photoshop, some settings are required. Before setting, it is best to close all open images. This process is completed by the "View → Proof Setting → Custom" command. Figure 7 shows the various proofing options. The meanings of the various proofing options are: Process CMYK, Process Cyan, Process Magenta, Process Yellow and Black, and Process CMY—Use the CMYK working space previously defined in the Color Settings dialog box to soft proof the image. Macintosh RGB and Windows RGB—Software proofing of images using standard Mac or Windows display characteristics files. Display RGB—Use the characteristic file of the display to soft proof the image. Simulate paper white—Let the user preview the color effect of adding the white background to the base color based on the current soft proofing profile. Simulate ink black—Let users preview the color effect of an image in a dynamic range based on the current soft proofing profile. Fourth, manage the color space of the image In a complete color management process, the conversion of color space is also an indispensable important link. In Photoshop 7, this function is completed through the "Specify Configuration File" and "Convert to Configuration File" commands in the "Image → Mode" menu. The "Specify Profile" command allows the user to specify any color space profile for the image. For example, many low-cost scanners do not support scanning profile files. In this case, you must use this function to assign profile files to images. In addition, this feature is also very useful when dealing with photos taken by digital cameras without embedded feature files. Figure 8 shows the characteristic file of the Kodak digital camera assigned to the picture. The "Convert to Profile" command allows the user to convert the color space of the image. For example, this command can be used when you want to apply the scanned color separation feature file to an image, and the converted feature file will automatically save the converted feature file when saving the image. Light therapy is suitable for depression prevention programs to play a huge role in the treatment of depression. When we start a beautiful day by bathing in the warm morning light every morning, full of energy in work and study, and full of hope for the future, as long as we have a well-made light therapy lamp, you can easily achieve this goal. Light Therapy Lamp Best,light Therapy Lamp for Depression,Light Therapy Lamp Guangdong Jishengke Industrial Co.,Ltd , https://www.jskpad.com
The Adobe Gamma utility is located in "My Computer → Control Panel". Before running Adobe Gamma, it is best to keep the monitor turned on for more than half an hour to ensure stable screen display. Turn off all desktop patterns and set the background color to light gray. To avoid interference with background colors. The operation interface of Adobe Gamma is shown in Figure 1. The specific steps are as follows:
2. After clicking the "Load" button, select the profile of the monitor or the closest.
3. Adjust the contrast of the monitor to the maximum value and adjust the brightness so that the middle frame is as dark as possible and the border is bright white.
4. For the "Fluorescent Agent" option, if you have the red, green and blue fluorescent agent values ​​given by the manufacturer, select "Custom", otherwise you can choose the "Trinitron" or "P22-EBU" type monitor .
5. For the setting of the monitor Gamma value, first check the single Gamma by dragging the slider so that the color of the middle box is as close as possible to the surrounding colors, and then check the Gamma values ​​of red, green and blue. The default value of Gamma is 2.2 in Windows and 1.8 in Mac.
6. For the selection of "Hardware Highlights", follow the display manufacturer's instructions to select the white field of the display to decide whether to use warm or cool colors. If there is no manufacturer's instructions, it is best to choose "6500K". Of course, you can also measure the white point of the display.
7. For "The most adjusted bright spot", it is best to select "Like hardware".
8. In the last step, click "Finish" to store the monitor profile.
February 20, 2024