CV-M9 GE
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8.3.4. Knee function
The video signal is digitized to 3x12-bit
and the most significant 3x8 or 3x10-bit
are presented at the output. By using a
look-up table function it is possible to
compress the video signal to change the
dynamic range. It can be done
individually for R, G and B with the Knee
Function.
O
u
tp
ut
C
a
m
er
a
Li
nk D
at
a Le
ve
l
1023
890
0
0
4095
Input CCD Data Level
2848
Knee Point = 37Ah (890)
Knee Slope = 080h (1/16)
In this case : Maximum Value is 968 LSB.
968
[100%]
32
[0%]
Knee Point
1279
102
1/16
Fig. 12. Knee function.
The Knee Function is given by 2 sets of
parameters. Knee point and slope. These
2 sets of data determine the relationship
between output and input data. This
conversion is done in hardware (FPGA)
using the knee data.
The normal transfer function is with a
slope 1:1. From a given point and up, the
slope can be changed. This point is the knee point
parameter, and its range is from 0 to 1023 referring to the video output.
The factory setting is 890.
The new slope can be set from 1:0 to 1:2.
A slope 1:0 is a clipper function, which will limit the output signal. A slope 1:2 will function as a
2 times contrast expanding function.
The slope parameter range is from 0 to 4095.
0 is slope 1:0.
2048 is slope 1:1.
4095 is slope 1:2.
The factory setting is 800, giving a slope of 800/2048 =1:0.39. All of the above is based on 3x10-
bit output.
8.3.5. ROI (Region of Interest)
The CV-M9GE allows two ROIs to be set. The ROI must not be overlapped.
The following is a matrix chart for ROI and Trigger modes. Please note that "ROI 2" and "ROI 1 +
ROI 2" is not a standard GenICam function.
For setting ROIs, use registers 0xA41C through 0xA43C.
Trigger Mode
ROI 1
ROI 2
ROI 1 + ROI 2
EPS Trigger
Yes
Yes
Yes
PWC Trigger
Yes
Yes
Yes
Sequential EPS Trigger
Yes (Note1)
No
No
Sequential PWC Trigger
Yes (Note1)
No
No
EPS Trigger Delayed Readout
Yes
No
No
PWC Trigger Delayed Readout
Yes
No
No
Sequential EPS Trigger Delayed Readout
Yes (Note1)
No
No
Sequential PWC Trigger Delayed Readout Yes (Note1)
No
No
Note 1: ROI 1 setting for "Sequential" must use registers 0xA808 through 0xA8A4 on register map.
