Canon FB630U - Manual (Page 42)

42
S T E P 4
An image scanned with Plug-in Module CS-U is a composite of individual square dots.
Each dot contains information that defines its level of brightness. Plug-in Module CS-U
can manipulate this data and reproduce adjusted images on the screen. This type of
data conversion is referred to a gamma adjustment.
The data created when the scanner scans an original is called input; the image
displayed on the screen is called output. When this input and output data are plotted
on the same curve, this is called a gamma curve. By changing the gamma curve, you
can adjust the brightness of an image.
Setting the Gamma
You can use one of four methods available in the Color Correction dialog box to set the
gamma curve. A description of each method is provided on the following pages.
Using the slider bar — Adjusts the
brightness and contrast of the original
image.
(p. 44)
Setting the gamma value — When you
cannot do the optimum setting with the
menu.
(p. 48)
Using the menu — Set to match the
display type.
(p. 46)
Setting the graph — Fine adjustment of
the gamma graph.
(p. 50)
Adjusting the Image with Gamma Settings
SCANNER
DISPLAY
Plug-in Module
Gamma curve
A straight or curved line indicates
the gamma status.
SHADOW
HIGHLIGHT
SHADOW
HIGHLIGHT
OUTPUT
BRIGHTNESS
INPUT BRIGHTNESS
The settings you perform in the Color Correction
dialog box can be saved to a file and opened
again whenever you need them.