Gain Auto - Basler acA2040-55 User Manual

Features

7.15.4 Gain Auto

Gain Auto is the "automatic" counterpart to manually setting the Gain parameter. When the gain
auto function is operational, the camera automatically adjusts the Gain parameter value within set
limits until a target average gray value for the pixel data from the related Auto Function ROI is
reached.
The gain auto function can be operated in the "once" and continuous" modes of operation.
If the related Auto Function ROI does not overlap the Image ROI (see the "Auto Function ROI"
section) the pixel data from the Auto Function ROI are not be used to control the gain. Instead, the
current manual setting for the Gain parameter value will control the gain.
Either Auto Function ROI can be selected to work with the balance white auto function.
The gain auto function and the exposure auto function can be used at the same time. In this case,
however, you must also set the auto function profile feature.
For more information about setting the gain "manually", see Section 7.2 on
For more information about the auto function profile feature, see Section 7.15.6 on
The limits within which the camera will adjust the Gain parameter are defined by the Auto Gain
Upper Limit and the Auto Gain Lower Limit parameters. The minimum and maximum allowed
settings for the Auto Gain Upper Limit and Auto Gain Lower Limit parameters depend on the current
pixel format, on the current settings for binning, and on whether or not the parameter limits for
manually setting the gain feature are disabled.
The Auto Target Brightness parameter defines the target average gray value that the gain auto
function will attempt to achieve when it is automatically adjusting the Gain value. The target average
gray value can range from 0 (black) to 255 (white) when the camera is set for an 8 bit pixel format
or from 0 (black) to 4095 (white) when the camera is set for a 12 bit pixel format.
To set the gain auto function using Basler pylon:
1. Select the Auto Function ROI, for example ROI1.
2. Set the value of the Offset X, Offset Y, Width, and Height parameters for the ROI.
3. Set the Gain Selector to All.
4. Set the value of the Auto Gain Lower Limit and Auto Gain Upper Limit parameters.
5. Set the value of the Auto Target Brightness parameter.
6. Set the value of the Gain Auto parameter for the "once" or the "continuous" mode of operation.
You can set the gain auto function from within your application software by using the pylon API. The
following code snippets illustrate using the API to set the gain auto function:
// Select auto function ROI 1 (as an example) to allow
// Gain Auto to control image brightness.
camera.AutoFunctionROISelector.SetValue
(AutoFunctionROISelector_ROI1);
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