Devicelink profiles are used to convert from one colour space to another bypassing the ICC Profile Connection Space, which is normally Lab. This allows devicelink profile creators to include specific functionality into the profile without relying on the CMS.
Using Devicelink profiles in Blackmagic and Megarip is simple. Open the Workbench application, navigate to the appropriate Media, click on the Colour Management tab, then use the Profile button in the Device Link section to assign the profile.
At times, it can be useful to process a job in Blackmagic or Megarip while maintaining the original colour values in the file. This is where null transform devicelink profiles can be used. For example, if you wanted to create a TIFF file from a PDF file you could use a Media setup with a null transform to ensure the original colour values remain unchanged.
These devicelink profiles simulate the way RGB to CMYK and CMYK to RGB conversions were performed during the 1980s, before colour management became widely adopted. Most CAD users relied on this form of conversion, so these can be useful to simulate that process.
Converts from CMYK to RGB using the following simple formulas
red = 255 - min(255, (cyan + black))
green = 255 - min(255, (magenta + black))
blue = 255 - min(255, (yellow + black))
Converts from RGB to CMYK using the following simple formulas
cyan = 255 - red
magenta = 255 - green
yellow = 255 - blue
black = min(cyan, magenta, yellow)
cyan = cyan - black
magenta = magenta - black
yellow = yellow - black