JAI AT-140GE - Manual (Page 36)

AT-140GE
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9.4.4 Blemish compensation
The AT-140GE has a blemish compensation circuit.
Blemish control has 0:OFF, 1:Black, 2:White and 3:Both. When 1, 2 or 3 is selected, the
stored factory data can be loaded.
Fig.30 Conceptual drawing for blemish compensation
9.4.5 Gamma setting (Look Up Table)
The AT-140GE has various gamma settings
including LUT (Look Up Table). Gamma can be
set OFF (1.0), 0.6, 0.45, or to exhibit
characteristics set using LUT.
The following shows the typical characteristics
in the case of gamma 0.6.
Fig.31. Gamma setting
CCD out Analog Signal Digital Out(32bit) Digital Out(24bit)
Black Setup 3.6%, 25mV 32LSB 8LSB
200mV 700mV 890LSB 222LSB
230mV↑ 800mV 1023LSB 255LSB
9.4.6 Knee compensation
If the relation of input and output is linear (1:1), the
output signal is saturated at a certain level of the
input signal and details cannot be reproduced in the
saturated area. The knee compensation circuit
maintains linear output up to a knee point and
compresses the level after the knee point. This is set
by a knee slope function. The AT-140GE supports up
to 200% signal compression by knee slope. Factory
default is OFF.
Fig.32 Example of Knee characteristics
Functions Data length Setting range
Knee Point 10bit 0LSB ～ 1023LSB
Knee Slope 12bit 0(x0.0005) ～ 4095(x2.0000)
Defective Pixel
Video Input
V
id
eo
O
ut
pu
t
Knee Slope
Knee Point
Analog Signal [mV]
Black Level
1023
890
32
0
25 700
Di
gi
ta
l
Ou
t
[L
SB
]
100% Level
White Clip Level
835