Gamma Correction
Gamma, or tone, correction, adjusts the light intensity ratio between the original image and the output data. It brings out more detail in areas of both highlight and shadow. When the image is reproduced on certain types of output devices, the tones of the image will be closer to those of the original. The term “gamma” (γ) means the shape and slant of the line on the graph that shows the ratio, as shown below.
Lighter
Data output
CRT Display A
CRT Display B
Printer Output A
Printer Output B
Printer Output C
Darker 
Lighter
Image input
Gamma correction provides five settings, and can be combined with all other scanner functions. Choose an appropriate setting from the five modes below.
❏CRT Display A
The output data is in proportion to the original image, as shown in the above graph. This setting is suited for most types of computer displays which can display an image in