How To Apply Color Management in Holiday-handmade Cards Photoshop

How to apply color management in holiday-handmade cards Photoshop

 

Color management is a very complex concept, and many people in the prepress field also have problems with not being able to set the relevant options and operations correctly in Photoshop software, which sometimes causes serious consequences in printing. In this paper, the classification of some problems often encountered in prepress enterprises is briefly explained, hoping to enlighten and help readers.

 

1. Overview setting and color management scheme

What should I do if the image file does not have or is embedded with the wrong ICC feature file (profile, Photoshop 5.x called overview, 6.X called color profile, meaning the same)? In the "Profile Settings" menu in Photoshop 5.x, you can set: 1) If the image file does not have an embedded ICC feature file, you can specify a assumed feature file and then convert it automatically; 2) If the feature file of the image does not match the current color Settings, you can select "Ignore", "convert" and "Ask when open" three options, whether you need to embed the ICC feature file when saving the image file, in Photoshop 5.x is also set in this menu; In Photoshop 6.x, the option to embed a feature file appears each time you save an image file.

 

Depending on the purpose of the image output, the "off", "preserve the embedded profile" and "Convert" options in the Photoshop 6.x color management scheme will have completely different effects. Here are some points to note when setting these three options.

 

Option: Off

Images without embedded property files will be processed within the currently defined working color space, and there is no assumed property file; If the embedded feature file of the image is inconsistent with the current color Settings, the original feature file of the image will be deleted, which effectively eliminates the color management function.

 

Option: Keep the embedded configuration file

This option is new to Photoshop6.0. The processing of images without embedded feature files is exactly the same as the option: "off"; If the embedded feature file of an image is inconsistent with the current color Settings, the image will still be displayed in the display in the colors described in the embedded feature file, and the current color Settings have no effect on the image. (Note: This option should be selected with caution, because it is possible that the image will appear very good on the monitor, but the final color will be greatly deviated when printed.)

 

Option: Conversion

If the feature file embedded in the image is inconsistent with the current color setting, the feature file is converted to the current color setting. For images without embedded feature files, you can specify a hypothetical feature file in Photoshop 5.x; In Photoshop 6.x, this option is no longer available.

 

2. Conversion of feature files

Usually the "Overview to Overview" (Photoshop 5.x) or "Convert to Profile" (Photoshop 6.x) submenu can be used to convert image properties files when opening images in Photoshop. This menu is available when you want to apply the scanning color separation feature file to an image or convert a CMYK image (for offset printing) to another form of CMYK image (for gravure printing).

 

Note: When Photoshop 5.x saves an image, the current working color space is embedded into the image as a feature file. Generally, only RGB, CMYK or Lab can be selected as the target color space. If you choose other feature files for conversion, such as: It is not the same as the current working color space, but when saving the image, Photoshop 5.x can only embed the current working color space as a feature file in the image, so it is possible to embed the wrong feature file! However, in Photoshop 6.x, this problem is no longer present, and the converted image automatically saves the feature file when it is saved. [next]

 

3. Color management in practice

There are many options for color management in Photoshop, and the following is a list of common production situations and solutions for reference.

 

1) RGB scanned image with feature file

At present, most of the high-end scanner software used in prepress enterprises can customize the output feature file, which lays the foundation for users to create an idealized color management mode, such as: Heidelberg scanning software NewColor can directly define the RGB output feature file in the "Profilmanager" submenu. As long as the output properties file in the scanning software is set to the "RGB Settings" menu in Photoshop, so that the image in Photoshop and NewColor screen display is approximately the same, this is an ideal color management in production.

 

Note: The ICC feature file must be stored in the "Windows→System→Color" folder on the PC. On a MAC, it is stored in the "System Folder →ColorSync Description file" folder, so that the corresponding ICC feature file can be called from the drop-down menu of the color Settings of different software.

 

2) RGB scan image file without feature file

Many inexpensive scanners do not support scanning feature files and do not provide IT8 standard originals for scanning correction. However, it is also possible to make scanning properties files for these scanners, because the properties software is completely independent of the input device! The color IT8 standard manuscript is scanned, and the characteristics of the scanner can be made. The scanning software that comes with these scanners usually does not support feature files, in which case the features in Photoshop must be used.

 

Open the image in Photoshop using "Overview to Overview" (Photoshop 5.x) or "Convert to Profile" (Photoshop 6.x) from the "Mode" menu (Figure 2).

 

Note: After creating the scanning features file, you cannot change the Settings in the scanner and scanning software (such as brightness, contrast, etc.), nor can you use the automatic function of the scanning software, as this conflicts with the features file! If you need to change the relevant Settings, you must also re-create the characteristics file that reflects the actual condition of the scanner.

 

3) RGB image file with "error" attribute file

What should I do when I open an RGB image with an embedded feature file, and the embedded feature file is different from the color

currently set in Photoshop?

 

If "Do not convert" is selected, the image data remains unchanged, but the color of the image on the display may change significantly; If you select Convert, the image data changes, but the colors the image displays may not be much different than before. Usually choosing "Convert" will give better results, so "Auto Convert" or "Ask when open" are recommended.

You can use "Preserve built-in overview" in Photoshop 6.x so that the image still appears as the built-in feature file, which is a convenient way for those RGB images that will eventually be converted to CMYK mode. If the RGB image still ends up in RGB mode, do not use this menu.

 

Note: Because the ICC properties file embedded in the image is not consistent with the Settings in Photoshop, the image will appear in the properties file mismatch dialog box when Photoshop opens, usually select Convert.

 

4) RGB image files without feature files

If an RGB image file does not have an embedded feature file, in general, you can select a feature file that is most commonly used by the operator in the "From" drop-down menu in the prompt box that opens the file, and select the corresponding CMYK or RGB mode in the "To" menu.

 

5) CMYK scan data with feature files

If you get a batch of scanned images, and the scanner operator tells you the color separation Settings at the time of scanning, or provides you with the corresponding ICC characteristics file, you can set it in the "CMYK Settings" or "CMYK working color Space".

Note: In the CMYK Settings menu, you can select or set a feature file that is consistent with the scanner for a better screen display.

From this can also be slightly extended, we can scan the image in the scanner to RGB mode, with the ICC property file we can do on every computer, whether it is a PC or a MAC, using the same color separation Settings, because sometimes using RGB images for image correction than CMYK has advantages, such as the use of all filters. RGB images are converted to CMYK images before final output; The same unfamiliar RGB images can be separated using the commonly used color separation properties file. A lot of the uncertainty created by using Photoshop's "Color Settings" menu is avoided! [next]

 

6) CMYK scan image without feature file

If you get a CMYK scan without a feature file, no matter how good the quality of these images, continue to work in Photoshop, which is often the case in prepress enterprises, because these images are already in CMYK mode, you can try to use the uncolor management function, That is, select "Do not embed profile" in Photoshop 5.x, and this option is available in Photoshop 6.x when stored.

The purpose of this setting is to protect the color of the image. If you do not disable the color management function in Photoshop and select the wrong Phot-oshop property file, it will cause the wrong color conversion!

 

7) CMYK image with "error" feature file

In principle, just like the RGB images mentioned earlier, "conversion" is usually selected, and the color loss caused by conversion between CMYK and CMYK is not as serious as that caused by conversion between RGB and RGB.

It should be noted here that different CMYK images (including gray image) feature files determine different numbers of black plates, for example: when gray image is converted into CMYK image, different color separation methods (feature files) are used to produce different numbers of black plates; For example, if a CMYK image uses GCR color separation with a high number of black plates, all this information will be lost if the conversion is directly selected when the color does not match! It is best to select "Ask when Open" for the above mentioned situations. This allows you to see what features are embedded in the CMYK image when you open the image. You can also select "do not convert" to open the image, see if the image can meet the needs of the output, and if possible, manually correct.

In Photoshop 6.x, there is a new function "preserve embedded profile", if you select the image that does not match the open feature file, the display will be displayed according to the original embedded feature file of the image, such as: the image with the image that is suitable for the gravure printing feature file will be pre-viewed on the display the actual effect of gravure printing; An image with a file suitable for newsprint printing features previews the actual effect of newsprint printing on the display.

 

8) CMYK image file without feature file

An assumed attribute file can be specified for CMYK images without a attribute file, and an assumed attribute file must be specified for image files saved long ago (such as Photoshop4.0 which does not support attribute files) before conversion.

 

4. Summary

Applying the color management options in Photoshop can be very convenient for the following main purposes:

 

· Improve image quality;

· The display in a workgroup is definitely inconsistent, and using RGB property files can make the image as consistent as possible on different monitors!

 

· The same CMYK image in a working group is definitely not consistent on different monitors, with the help of device-independent ICC features file these issues can also be resolved!

 

· Images can be exchanged between PC and Mac with minimal color loss;

 

· An image can be converted through different ICC feature files, so that the same image can be applied to different output processes;

· Cheaper printers can be used as digital proofing equipment. Although there are different RIP solutions for color management, they are all expensive, and some color management features in Photoshop and other software can be used to use inexpensive inkjet printing to get a preview of the final print, which can be a serious challenge for some expensive color management workflows!