Blackfly - CYLOD

Point Grey Blackfly Technical Reference
8 Blackfly Attributes
8.11 Auto Exposure
Auto exposure allows the camera to automatically control exposure and/or gain in order to achieve a specific average
image intensity. Additionally, users can specify the range of allowed values used by the auto-exposure algorithm by
setting the auto exposure range, the auto shutter range, and the auto gain range.
Auto Exposure allows the user to control the camera system’s automatic exposure algorithm. It has three useful
states:
State
Off
Manual Exposure Control
Auto Exposure Control
Description
Control of the exposure is achieved via setting both Exposure and Gain. This mode is achieved by
setting Auto Exposure to Off, or by setting Exposure and Gain to Off.
The camera automatically modifies Exposure and Gain to try to match the average image
intensity to the Auto Exposure value. This mode is achieved by setting Auto Exposure to Off and
either/both of Exposure and Gain to Continuous.
The camera automatically modifies the value in order to produce an image that is visually
pleasing. This mode is achieved by setting the all three of Auto Exposure, Exposure, and Gain to
Continuous. In this mode, the value reflects the average image intensity.
Auto Exposure can only control the exposure when Exposure and/or Gain are set to Continuous. If only one of the
settings is in "auto" mode then the auto exposure controller attempts to control the image intensity using just that one
setting. If both of these settings are in "auto" mode the auto exposure controller uses a exposure-before-gain heuristic
to try and maximize the signal-to-noise ratio by favoring a longer exposure time over a larger gain value.
The auto exposure algorithm is only applied to the active region of interest, and not the entire array of active pixels.
There are four parameters that affect Auto Exposure:
Auto Exposure Range—Allows the user to specify the range of allowed exposure values to be used by the automatic
exposure controller when in auto mode.
Auto Shutter Range—Allows the user to specify the range of exposure values to be used by the automatic exposure
controller which is generally some subset of the entire exposure range.
Auto Gain Range—Allows the user to specify the range of gain values to be used by the automatic exposure controller
which is generally some subset of the entire gain range.
Auto Exposure ROI—Allows the user to specify a region of interest within the full image to be used for both auto
exposure and white balance. The ROI position and size are relative to the transmitted image. If the request ROI is of
zero width or height, the entire image is used.
Access this feature using:
GenICam
Acquisition Control
CSR control: AE_ROI: 1A70 – 1A74h
Revised 12/13/2012
Copyright ©2012 Point Grey Research Inc.
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