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HP PrecisionScan Pro User’s Guide 87
Adjusting images of
pictures
Book Contents Index
➮
➮
Set color channel for black and white bitmaps
When you want to save a black and white bitmap
of a picture that has been printed or photocopied
on colored paper, or want to create a special
effect, you can change the color channel used in
the final scan.
Eliminating a color from the image
By changing the color channel setting in the Black
& White Threshold
tool you can eliminate red, green
or blue from the image (see page
88).
1 Scan a picture.
2 From the Tools menu, select B & W Threshold.
The
Black & White Threshold tool appears.
3 From the Output Type menu, select Black & White
Bitmap (raster)
.
The image changes to black and white.
4 Decrease the value for the black and white
threshold (see page
86).
5 Select a color channel from the Scan using
channel
list box in the Black & White Threshold
tool:
■
To eliminate all the red in colored line art or
from a drawing printed on red or pink paper,
choose the
Red channel. The red components of
each pixel in the image will be mapped to white
and green and blue components of each pixel
will be mapped to black.
■
To eliminate all the green in colored line art or
from a drawing printed on green paper, choose
the
Green channel. The green components of
each pixel in the image will be mapped to white
and red and blue components of each pixel will
be mapped to black.
■
To eliminate all the blue in colored line art or
from a drawing printed on blue paper, choose
the
Blue channel. The blue components of each
pixel in the image will be mapped to white and
red and green components of each pixel will be
mapped to black.
The
Auto button in the Black & White
Threshold
tool does not reset the color
channel.
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