Abstract: A method for transforming an image, containing an arbitrary number of colors from a full color process printing mode to a spot color printing mode while preserving the user's intended color usage as much as possible. The method is contained in a utility and referred to as “Spot Color Transformation” (SCT). The SCT utility provides a user the ability to transform an image generated by a computer program module, such as a desktop publishing computer program module, from a full color mode into a spot color mode. The SCT utility operates on an object-by-object basis to map objects within an image to one of several partitions: a black partition and a color partition. The SCT utility maps each object that has an associated color that is substantially black or a tint of black to the black partition. Next, the SCT utility converts the colors of unmapped objects to a tint of the spot color based on the luminance value of the particular color relative to the lowest luminance value found in the image.

Abstract: A method for color separating an image stored in an encapsulated POSTSCRIPT (EPS) file to be printed to a spot-color printing plate. The method is contained in a utility and referred to as “Encapsulated POSTCRIPT Color Separation” (ECS). The color separation of images in an EPS file is a two-step process. In the first step, the ECS utility determines whether the spot color appears in the electronic file. Typically, the named colors are listed in the document structuring convention (“DSC”) comments of the header portion of the electronic file. If the DSC comment section contains a named color, then the ECS utility sets a key color to the named color. However, if the DSC comment section does not contain a named color, then the ECS defines the key color with the spot color defined by the DTP application. The ECS utility creates customized versions of the POSTSCRIPT language operators that define the colors of each object, and sends these customized versions to the POSTSCRIPT printer.