Microtek ScanMaker 3600 User Manual page 54

256 Colors (Default)/256 Colors (Custom)
These are single-channel images (8 bits per pixel) that use a color
lookup table containing up to 256 colors. The file size is smaller for
images in this mode. As an initial setting, selecting 256 Colors
(Default) uses an Adaptive palette with Diffusion. If the 256 Colors
(Custom) option is selected, the dialog box will appear.
Palette: The Palette option lets you choose the method for creating
the color palette table. Uniform uses a 6-6-6 fixed color palette
table. Adaptive (default) creates a color palette table from the more
commonly used areas of the color spectrum that appears in the
image.
Dither: The Dither option can improve the color quality of the 256-
indexed color image for photographs or continuous-tone images,
using a technique of mixing available colors to simulate missing
colors. None provides no dithering. Pattern uses a structured
pattern to simulate missing colors. Diffusion (default) uses the error
diffusion technique to dither colors and produces the best quality for
256 colors.
Resolution/Res
Resolution/Res is the sampling of image pixel per measurement
unit or the amount of pixel information stored in an image.
Together, the image resolution and dimensions determine the file
size of the image, which is measured in kilobytes (KB) or
megabytes (MB).
The resolution of an image is important in determining the quality of
the output image. Resolution is also directly related to file size, and
the higher the resolution, the larger the resulting file size will be.
When dealing with resolution, remember to distinguish between
optical resolution and interpolated resolution.
Optical resolution is the "real" resolution as measured by the