Color image color separation parameter setting (2)

(2) Defining ink paper combinations

If the user's ink and paper cannot be found in the menu, you can get the lnk C in the dialog box according to the actually used ink and paper proofing. Select the custom item in the colors pull-down menu to open the Custom Ink Paper Assembly dialog box (shown in Figure 2). The Yxy coordinate values ​​can be converted to L*a*b* coordinate values ​​by clicking on the L*a*b* coordinates in the lower left corner of the dialog box.

2. Dot Gains

Dot enlargement is an unavoidable problem in the printing process. The dot gain value here indicates the dot gain value at the 50% gradation. The value setting should be set according to the printing situation, with the increase of the increase value. When separating colors, the corresponding data should be reduced to compensate for the dot gain during printing.

If the default midtone dot gain value does not meet the requirements, you can set it yourself. Select “Curve” item in “Color dot increase” drop-down menu of color separation parameter dialog box, and open the custom dot gain curve dialog box to set the dot gain curve. The dot gain value can be set uniformly or separately in different color separation channels.

Color separation option (5eparation Option)

The 5eparation option includes five options: separation type selection, black generation option, background gain, black ink limit, and total ink limit.

1. Separation type selection

The choice of color separation type is GCR (Gray Component Rep]ace, gray component replacement) and UCR (Under Color Remova), color removal). The default is GCR color separation, which is suitable for originals with large dark areas, gray color, and color supplements, such as Chinese paintings, prints, mechanical drawings, etc. UCR is applicable to originals that are mainly colored and have less grey components. Such as scenery, portrait photography.

(to be continued)