Color management is a very complex concept, and many staff in the prepress area still have problems setting the right options and operations in Photoshop software so that they sometimes have serious consequences in printing. This article briefly describes the classification of some issues that are often encountered in prepress businesses, with a view to providing readers with inspiration and help.
1. Overview settings and color management solutions
If the image file is missing or has an incorrect ICC profile (profile, profile in Photoshop 5.X, 6.X color profile, same meaning), what should be done? Can be set in the "Profile Settings" menu in Photoshop5.X: 1) If the image file is not embedded in the ICC profile, you can specify a hypothetical profile and then automatically convert it; 2) If the profile of the image and the current color Settings do not match, you can choose "ignore", "conversion" and "open when asked" three options, save the image file need to be embedded in the ICC profile, in Photoshop5.X is also set in this menu; and in Photoshop6 The option to embed a property file occurs every time .X saves an image file.
Depending on the output of the image, Photoshop6. The "Off", "Retain embedded profile", and "Transfer" options in the X color management scheme have completely different effects. Let's talk about the places to note when setting these three options.
Options: Off
An image without an embedded profile will be processed within the currently defined working color space, and there is no assumed profile at the same time; if the profile embedded in the image does not match the current color settings, the profile of the original image will be Removed, this option is equivalent to eliminating the color management function.
Options: Keep embedded profile
This option is new in Photoshop 6.0. The processing of an image without an embedded profile is exactly the same as the option: "Off"; if the image embedded profile does not match the current color settings, the image is still displayed on the display according to the color described in the embedded profile, current Color settings have no effect on this image. (Note: This option should be used with caution because it is possible that the image is displayed very well on the monitor, but the color will eventually be greatly deviated when printed.)
Options: Conversion
If the profile embedded in the image does not match the current color settings, the profile is converted to the current color setting. For images without embedded profile files in Photoshop 5. A hypothetical profile can be specified in X; in Photoshop 6. X has no such option.
2, the characteristics of the file conversion
You can use the Overview to Profile (Photoshop5.X) or Convert to Profile (Photoshop6.X) submenus to open the image properties file when you open the image in Photoshop. You can use this menu when you want to apply a scanned separation profile to an image or convert a CMYK image (for offset printing) to another form of CMYK image (for gravure printing).
Note: Photoshop5. When X saves an image, the current working color space is embedded into the image as a characteristic file. Generally, only RGB, CMYK, or Lab can be selected as the target color space. If other characteristic files are selected for conversion, for example, it is different from the current working color space. , but when saving the image, Photoshop5. X can only embed the current working color space as a profile in the image, so it is possible to embed the wrong profile! And in Photoshop 6. In X, this problem no longer exists. The converted image of the feature file is automatically saved when it is saved.