6) CMYK scan image without profile
If you get CMYK scanned images without a profile, no matter how good the quality of these images, you have to continue processing in Photoshop, which is a common situation in prepress companies, because these images are already in CMYK mode, You can try to use the cancel color management feature, that is, select "do not embed profile" in Photoshop 5.X, and this option is stored in Photoshop6.X.
The purpose of this setting is to protect the image colors. If you do not cancel the color management function in Photoshop and select the wrong Phot-oshop feature file will lead to wrong color conversion!
7) CMYK image with "error" profile
In principle, as with the aforementioned RGB image, “Conversion†is usually selected, and the color loss caused by the conversion between CMYK and CMYK is not as severe as the conversion from RGB to RGB.
One thing to note here is that the different profiles of CMYK images (including grayscale images) determine the number of different blackplates. For example, when the grayscale image is converted to a CMYK image, different separation methods (characteristic files) are used. Produce a different number of black editions; for example, if a CMYK image uses a GCR color separation method with a higher number of black editions, if the color is not directly matched when a mismatch occurs, all of this information will be lost! It is best to choose "Ask when opening" for the above mentioned situation. This allows you to see what kind of profile the CMYK image embeds when you open the image. You can also select "Do not convert" to open the image to see if the image meets the output requirements and correct it manually if possible.
There is a new feature in Photoshop 6.X, “Preserve embedded profile.†If you select an image that does not match the open profile, the display will be displayed according to the image's original embedded profile, such as with a profile suitable for gravure printing. The image previews the actual effect of gravure printing on the display; images with a file suitable for newsprint print characteristics preview the actual effect of newsprint printing on the display.
8) CMYK image files without a profile
For a CMYK image without a property file, you can specify a hypothetical property file. For image files that were saved long ago (such as Photoshop 4.0 does not support property files), you must specify a hypothetical property file before converting.
4, summary
Using the color management options in Photoshop makes it easy to achieve the following main goals:
Improve the quality of the image;
• The display in a working group is definitely inconsistent. Using RGB profiles allows the images to be nearly identical on different monitors!
• The same CMYK images in a working group are certainly not consistent on different displays. These issues can also be resolved with device-independent ICC profiles!
Image can be exchanged between PC and Mac with minimal color loss;
· An image can be converted by using different ICC profiles, so that the same image can be applied to different output processes;
• Cheaper printers can be used as digital proofing devices. Although there are different RIP solutions for color management, the prices are relatively expensive. Some color management functions in Photoshop and Other software can use inexpensive ink-jet printing to obtain proofs that can preview the final print. This is at some price. The expensive color management workflow cannot but be said to be a daunting challenge!