Image Functions
3-10
3.2.4
Halftone reading
This scanner supports two types of halftone image, that is Dither and Error Diffusion.
NOTICE: The density of the halftone can not be adjusted by the Threshold in Table 3.4 but the
Brightness in Table 3.5.
(1)
Dither
This is a way of producing halftone images with white and black pixels. The scanned image is
processed by the unit of group of pixels.
At first a reference table called “dither matrix” is specified. Each element in the matrix (8x8)
has a threshold value of 256 levels. Allocation of threshold values in the dither matrix is called
“dither pattern”. Group of the scanned images are compared with the dither pattern, and each
element is decided whether it is black or white. Number of black pixels corresponds to a level
of scale, producing pseudo grayscale images.
Four built-in dither patterns are available. Parameters which affect dither are shown in Table
3.7.
Table 3.7 Parameter of dither
Parameter
Control register No.
value
Default
Halftone reading ON
A#2/B#2
B’xxxx11xx’
ON
Dither ON
A#19/B#19
B’xxxx000x’
8 step setting ON
A#19
B’xxxxxxx0’
set from operator panel
Light
Normal
Dark
A#1/B#1
B’xxxx00xx’
B’xxxx1000’
to
B’xxxx1100
to
B’xxxx1111’
256 step setting ON
A#19
B’xxxxxxx1’
Density *1
Light
to
Dark
A#20/B#20
X’01’
to
X’FF’
Set from
operator
panel
Contrast
Mostly soft contrast
Normal
Mostly sharp contrast
A#21/B#21
X’01’
to
X’80’
to
X’FF’
X’80’
0
B’0000xxxx’
1
B’0001xxxx’
2
B’0010xxxx’
Bult-in
3
B’0011xxxx’
0
B’1000xxxx’
to
to
Dither
pattern No.
Download *2
7
A#2/B#2
B’1111xxxx’
*1
Effective only for Built-in pattern
*2
IPC-2D or OPC-3D required. (See section 3.3.5)
Summary of Contents for M3097DE
Page 1: ...C150 E102 01EN M3097DE Image Scanner OEM Manual...
Page 2: ......
Page 4: ...This page is intentionally left blank...
Page 42: ...3 3 Optional image function 3 21...
Page 43: ...Image Functions 3 22 The conceptual image processing flow in the IPC mode is shown below...
Page 45: ...Image Functions 3 24...
Page 70: ...5 3 Cleaning 5 15 Two rollers are included Figure 5 5 Pick roller...
Page 73: ...6 3 Figure 6 1 Jam clearance...
Page 197: ...Scanner Interface Appendix A 124 5 Dimensions of the board For M3093EX DE and M3097DE...
