ALLIED Vision Technologies Marlin F-201 - Manual (Page 69)

Description of the data path
MARLIN Technical Manual V2.4.0
69
Example Adjust image so that the dark areas are well displayed. Calculate the used
shutter time. Activate HDR mode.
Assuming shutter time to be 40 ms = 40,000 µs:
• Kneepoint_1 = 10 % * 40,000 µs = 4,000 µs = 0xFA0
• Kneepoint_2 = 5 % * 40,000 µs = 2,000 µs = 0x7D0
• Kneepoint_3 = 2.5 % * 40,000 µs = 1,000 µs = 0x3E8
The following needs to be written:
For further tuning, readjust KNEEPOINT_X but maintain ratio KNEEPOINT_1 >
KNEEPOINT_2 > KNEEPOINT_3.
The figure below, taken from the sensor's data sheet, illustrates the nonlinear
behavior of the photo response curve in dual slope mode.
Name Address Write the following
HDR_CONTROL: (Address: 0xF1000280) 0x02000003
KNEEPOINT_1: (Address: 0xF1000284) 0x00000FA0
KNEEPOINT_2: (Address: 0xF1000288) 0x000007D0
KNEEPOINT_3: (Address: 0xF100028C) 0x000003E8
Table 28: Example: 3 knee-points
Figure 35: IBIS5A nonlinear photo response curve with two slopes