Hi Everybody,
I don't want to get into an argument over Black Point Compensation (scaling ?).I just want to know if I can turn it on and off - preferably in Photopaint X6.
COSTCO photo asks that it be turned on when soft proofing files for their prints.So far, I have used COSTCO's profiles to soft proof with Black Point Compensation in Photoshop CS5.Can this be done in Photopaint X6.
PhilPS: Should it be of any interest, I'll explain what Black Point Compensation (scaling ?) does.
CorelDraw Graphics Suite does not support black point compensation. As far as I can tell black point compensation is not ICC compliant.
Black point compensation only works with relative colorimetric rendering intent, then when used it renders the conversions very close to perceptual rendering. Turning BPC on or off is something that they would do for the conversion process to their media profile not something you would do if sending an RGB image to them for output.
I'm posting a screen capture of an RGB image converted to CMYK using relative colorimetric no BPC, with BPC turned on and perceptual rendering. Take a look at the post and shadow areas top left corner of the image. Perceptual rendering does the best conversion to CMYK. BTW I used PS for the BPC conversion and set PP and PS to use the same color engine MS ICM CMM 3.
This quote below is from from the ICC white paper 40 dated 2007 which is about 4 or 5 years after development of BPC. BPC was originally created to compensate for a common malady at that time, what Adobe called malformed ICC profiles. That condition has for the very large part been eliminated by 2009.
BPC makes an important contribution to the ICC workflow and can be implemented with minimal change to existing color architectures. It adds value that many users have come to depend on, particularly for Relative Colorimetric RI, which has little value without BPC. This is particularly important for proofing.
Thus, BPC has no adverse effect on the Perceptual and Saturation transforms of properly formed profiles. There are atypical profiles (Adobe calls them “malformed”), however, in which BPC may actually be beneficial for Perceptual or Saturation processing. An example of this is provided by one of the sRGB profiles, sRGB_IEC61966-2-1_no_black_scaling.icc which is available on the ICC website, http://www.color.org/srgbprofiles.html.
In practice, the results may not be exactly according to theory. Typically, though, BPC has little or no effect on the Perceptual and Saturation RIs. (BPC is generally disallowed for the Absolute Colorimetric RI, since it is contrary to the spirit in which that RI is defined.)
I never use BPC or relative colorimetric rendering for RGB to CMYK conversions.
I use relative colorimetric only for CMYK to CMYK conversions if the TIC is very close.