4
HP PrecisionScan Pro User’s Guide 88
Adjusting images of
pictures
Book Contents Index
Examples of changing color channels
Images of a color drawing changed to the Black &
White Bitmap (raster)
output type are shown with
different color channels and black and white
threshold settings applied in the
Black & White
Threshold
tool.
Original with True Color output
type
Black & White Bitmap (raster)
output type applied with
NTSC
Gray
color
channel and
automatic
threshold (110)
Red color channel and
automatic threshold (110)
Green color channel and
automatic threshold (110)
Blue color channel and automatic
threshold (110)
Blue color channel and higher
threshold (173)
The NTSC Gray channel in the Scan using
channel
list box of the Black & White
Threshold
tool converts color to gray at a
ratio of 30% red, 59% green, and 11% blue.
TIP
