3 December 2004
IMAGE PROCESSING
6-13
D
etailed
D
escr
iptions
Color resolution
Because of the differences in color space, the color observed by a person, and the
color value sensed by the CCD can vary. Color resolution corrects the color data
gathered by the CCD. It uses a color table that adjusts for the way particular colors
are displayed on specific CRTs. This allows a more-natural representation of the
scanned image. This also changes RGB signals to YCC signals. After adjusting
color resolution, this changes YCC signals to RGB signals again.
Background erase
Background can be erased with this function using threshold value.
Auto binary processing
When making simple binary scans of a light original (e.g. gray text on a white
background), the threshold level is adjusted. This allows the lighter shades to
appear in the final image.
Auto image area separation
When a scanned document contains text and photo areas, the machine searches
for the outlines of the text. Based on these outlines, it separates the image into text
and photo areas. Text areas use simple binary processing. Photo areas use
dithering and error diffusion.
Filtering
There are two software filters: the MTF (Modulation Transfer Function) filter and
the smoothing filter. The MTF filter emphasizes sharpness, and is used with
documents that contain both text and photo areas. The smoothing filter is only used
for photo-image documents.
