Dots Per Inch; Dither; Custom Dither (Halftone) Patterns - Bell and Howell Tr?per Feature Manual

This function specifies the resolution DPI (dots per inch) for the main and subdocument scanning
parameters. The available resolution setting ranges are 100 to 600 dpi. The typical dpi setting is 200 for
bitonal documents and 150 for color documents.
When the resolution is increased, the image becomes clearer. However, the image file size increases, PC
HDD (Hard Disk Drive) free space decreases and additional scanning time increases. For regular high dpi
scanning, you may consider purchasing a memory upgrade kit to increase the scanning speed.
The Dither mode is primarily used for black and white photographs. It accelerates scanning speed by
transforming a grayscale image to a black and white image. The first and least apparent adjustment can be
made with the Error Diffusion filter, then a little more with Bayer Dither 64, then Bayer Dither 16, 45 deg.
Halftone, and finally, for the most extreme transformation, 0 deg. Halftone.
Note
Error Diffusion cannot be used when Autocrop, Deskew or Dynamic Threshold are selected.
You can also use the User Download option to select a customized dither pattern. For information on
creating custom dither patterns, refer to the next section,
page 28.
Using the ISlS driver, the Halftone (dither) patterns can be customized. This function specifies the DPI
(dots per inch) for the main and subdocument scanning parameters. The available resolution setting
ranges are 100 to 600 dpi. The typical dpi setting is 200 for bitonal documents and 150 for color documents
. When the resolution is increased, the image becomes clearer. However, the image file size increases, PC
HDD (Hard Disk Drive) free space decreases and additional scanning time increases. For regular high dpi
scanning, you may consider purchasing a memory upgrade kit to increase the scanning speed.
When setting the dpi, you can either select a preset number from the drop-down list or type in the desired
dpi.
Note
When using either the Black and White, Binary&Color or Binary&Gray mode, the color or gray image
resolution can be set to a ratio of 111, 112, 113 or 714 dpi of the black and white resolution. However,
the color resolution cannot be set outside the 100 to 600 dpi range. See details on the MultiStream
mode within the ISIS scanning software application or
"3.1.3.1 Custom Dither (Halftone) Patterns" on

3.1.3.1 Custom Dither (Halftone) Patterns

"3.1.1 Mode" on page
www.bbhscanners.com

3.1.2 Dots per inch

3.1.3 Dither

27.
28 of 48