Dalsa Genie Nano Series, Руководство пользователя

Страница: 39 / 113

Nano Series GigE Vision Camera Operational Reference
•
37
Offset/Gain Control Details
Applies to Nano models using Sony IMX174/249 sensors (Monochrome or Color)
The Gain and Black level functions are applied at the sensor and/or on the digital image values
output by the sensor, as described below.
• Gain Selector = Sensor: The gain function controls the sensor hardware. Sensor gain is
applied first by an analog amplifier (from 0 to +24dB) and then continues automatically via a
digital amplifier (from +25 to +54 dB). Note that digital noise increases linearly with higher
gain values.
•
Gain: Values are a linear range from 1 to n in 0.01 steps. The entered value is automatically
converted to dB to control sensor gain. Users can also control gain via the Gain(Raw) feature.
•
Gain (Raw): An alternative method to control sensor gain, where values entered represent
0.1dB increments. The value range is 0 to 480 which controls a 0 to 48dB gain range.
•
Black Level: This offset variable exists within the sensor. The Sony sensors allow an offset
range between 0 and 511 DN. The factory settings default value for each sensor used by
various Nano models, is recommended as per the sensor manufacturer design specifications.
Note: With the factory default offset, testing a camera’s black output in 8-bit mode may show
a 2 DN value difference across the image. Changing the Black Level value up or down will push
sensor noise (present at the sensors native bits per pixel) to fall within one 8-bit value, thus the
noise becomes hidden.
•
Gain Selector = Digital: The gain function controls the post sensor digital amplifier (available
only on some models of Nano cameras). This gain factor is independent of any sensor gain set.
This setting is a linear number range of 1 to 4 in 0.1 steps).
Sensor Gain Control
Post Digital Gain Control
Sensor Gain Stages
Analog Digital
Black Level
Control
Digital