Filter
Top Products
3.3 Optional image function
3-15
(2) Gradation
[A.4.7 SET WINDOW command / DTC mode]
Gradation specifies the gamma curve correction before processing Dynamic Threshold. When
scanning news papers or old documents which background is dark, it is desirable that the gamma
curve has coarse steps in the lighter side and fine steps in the darker side. This is called High
Contrast gamma curve.
γ curve
As the Dynamic Threshold with IPC-3D includes an automatic contrast adjustment, High Contrast
setting is not required.
Table 3.8 Parameter of Gradation
Parameter Value Effect with IPC-2D Effect with IPC-3D Default
Ordinary X’xxx00xxx’ Normal gamma curve
(for general document)
Normal gamma
curve
High Contrast X’xxx10xxx’ Makes low contrast Image
clear
No effect
X’00’
* for dark background document such as newspaper or old document