Xerox 6180N Color Management Guide v3.7 - Page 12

DocuSP color management • The incoming job contains embedded profiles that result in the printer driver creating a Color Space Array (CSA) for the color data. These PDL instructions are honored by the system. Xerox enhanced path Incoming RGB or CMYK data uses the DocuSP Xerox Enhanced Path Look Up Table (LUT) or Emulation LUT when performing the SWOP™ CMYK to DocuSP print engine CMYK transformation. Benefits of using this path include: • Faster RIP time via use of the LUTs as contrasted with the ICC Path. • This path preserves the Black (K) channel and Black darkness. Look Up Tables provide a quick, effective translation from the source space to the specific printer's CMYK space. These tables are faster because the CMYK values are translated directly to output space, instead of first being translated to deviceindependent space and then to the print-engine-specific space. RGB data is converted using 3 x 4 LUTs. 4 x 4 LUTs provide direct CMYK to CMYK mapping, preserving black. When pure black is passed through a source profile (ICC profile path), it is converted to XYZ. Once in XYZ, there is no way for the color management system to know that the color was originally pure black. Thus, pure K is converted to a CMYK combination (Gray Component Removal, or GCR, is involved in this process). In contrast, the 4 x 4 tables recognize pure K and output the appropriate K for the source-to-destination mapping. The following conditions guarantee a job follows the Xerox enhanced path: • The incoming job is untagged and using a pre-installed output profile. • A Xerox stock is programmed for the job • A non-Xerox stock that is a member of an unaltered Xerox color group is programmed for the job • A Xerox output color profile, included with the system, has been assigned to the job 2-4 Color Management Guide