Home | Contact Us | Submit Troubleshooting Info | Search | Help
Output | Software Solutions | Proofing | Color, Screening and Calibration | Scanning | Digital Photography | Consumables | POS
Home | Contact Us | Submit Troubleshooting Info | Search | Help
Output | Software Solutions | Proofing | Color, Screening and Calibration | Scanning | Digital Photography | Consumables | POS
|
|
||
Product |
Prinergy 1.1; Prinergy Connect 2.0 | |
Platform |
||
Operating system |
||
|
|
||
Error |
||
|
|
||
Symptoms |
An image from Photoshop saved as an EPS with PostScript Color Management enabled ends up with a different color than the same image saved as a TIFF (which does not have the PostScript color management option). It is not possible in Prinergy 2.0.x or earlier to use the Color Matcher or any other means to strip out this difference. |
|
|
|
||
Cause |
When you save a CMYK EPS file from Photoshop with PostScript Color Management enabled, a PostScript CSA (color space array) is also saved into the file to translate it into a CIE-based colorspace. Like an ICC profile, the purpose of the CSA is to provide a mapping from device color coordinates (CMYK) into device-independent coordinates (in the case of CSA, XYZ, which is directly transformable into L*a*b*). The original CMYK pixel data is retained separately in the EPS. What happens in Distiller 4 is that an EPS with PostScript Color Management enabled turns into a Lab image. While somewhat correct, this does not preserve the separation in the data between the color mapping (CSA) and the image data (CMYK). There is no way for the color engine to recover the original CMYK data from this, like there is no way to recover (short of undo) from having run a convert to profile in Photoshop. In Distiller 5, the same file turns into a CMYK image that has been tagged with an ICC profile, which Distiller 5 builds up out of the information in the CSA. (Technically, we get an image in a 4-component ICCBased colorspace.) Because there is now an ICC profile, the Color Matcher is able to strip it out. One of the changes in Prinergy 2.1 is the upgrade of the Normalizer to use the Distiller 5 core. Prinergy 2.0.7 and earlier uses the Distiller 4 core, which is why, if you run a file with PostScript Color Management through Prinergy today, you'll see the file converted to the Lab colorspace. Using Prinergy 2.1, you get the desired result. |
|
|
|
||
Solution |
Either wait for Prinergy 2.1 (which uses the Distiller 5 core for the Normalizer), or use Distiller 5 to process the pages. This will result in a file with images with embedded ICC profiles, which the Color Matcher is able to strip out. Note that running PDF files processed through Distiller 4 or Prinergy 1.x/2.0.x back through Distiller 5 will not help. You must go back to the PostScript. However, this means that you do not have to go all the way back to Photoshop and re-save and re-pour. Permanent fix: |
|
|
|
||
See also |
||
|
|
||
Keywords |
color, Photoshop, PostScript, refiner |
|
|
|
||
Technical contact(s) |
Marney Butlin |
|
Submitted by |
William Li |
|
Date submitted |
06 May 2002 |
|