Epson GT-30000 - Manual (Page 15)

Scanner Settings
11
Downloading a Gamma Table
After you have created one or more gamma table files as described above, you must download the desired
one to the scanner. To do this, follow these steps:
1. In the Advanced Settings dialog box (which appears after clicking More in the Scanner Settings
dialog box), click the appropriate Gamma button:
•
Gray Gamma
Select a grayscale gamma file to download to the scanner.
•
Red Gamma
Select a red gamma file to download to the scanner.
•
Green Gamma
Select a green gamma file to download to the scanner.
•
Blue Gamma
Select a blue gamma file to download to the scanner.
The following dialog box appears:
2. Navigate to the desired directory using the dialog controls. Usually, this should be the Pixtran
subdirectory of the Windows directory (or Winnt, if you are using Windows NT).
3. Choose the desired gamma table file, then click OK.
4. Remember to choose User defined in the Gamma list of the Advanced Settings dialog box to enable
the downloaded gamma table.
Note
A downloaded gamma table remains in the scanner until the power is turned off,
the scanner is reset, or the table is replaced by downloading another table.
Creating a Dither Pattern File
To create a dither pattern file for the EPSON GT-30000 scanner, use a text editor or word processor
capable of saving plain text (ASCII) files. Dither patterns are specified as a matrix of values. The purpose
of a dither pattern matrix is to simulate halftoning (converting shades of gray to patterns of black and white
dots) in such as way as to avoid aliasing. Aliasing is the appearance of repeating patterns such as lines or
stripes in the image. Specification of the values for dither threshold files is complex and beyond the scope
of this document. If you are inexperienced with dither algorithms, you should use the built-in dither
patterns. Follow these steps to create a dither pattern file: