Direct ICC Profile Support Internally Within PS/PDF for High Speed Color Printer
Publication Date: 2011-Sep-16
The IP.com Prior Art Database
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Direct ICC profile support internally within PostScript/PDF for high speed
In PostScript color management, CIEBased input color is converted to CMYK using CSA (Color Space Array) and CRD (Color Rendering Dictionary). With pervasive of ICC profiles, printers need to support ICC profiles. A typical way is to convert Input ICC profiles to CSAs and Output ICC profile to CRD. Then using PostScript color management to convert from all input color spaces to CMYK output color space. There are a few drawbacks with this mechanism.
PostScript internal color management is an older color management system as compare to ICC color management. It has some limitation. For example, output ICC profile supports media white point Y<1, CRD does not allow white point Y<1. ICC supports link profile for performance improvement, PostScript Color Management (CM) must go through CSA and CRD which means two steps for color conversion.
The proposed method uses OCA(Output Color Adjustment) interface to convert input color to output color with ICC profile in a single step inside the PostScript/PDF Configurable PostScript Interpreter (CPSI Rip). It also will bypass PostScript CSA and CRD processing. DeviceLink LUTs(Look Up Tables) are built with input and output ICC profiles to improve performance. The known solution is to convert input and output ICC profiles into CSA and CRD first, then using PostScript internal color management.
The figure below shows different input data processing paths
1) Device input color with input/output ICC profiles
Input device color is converted to intermediate generic CMYK using PostScript default device conversion first, then we convert to device CMYK using the corresponding link LUT through PostScript OCA(Out...