Basler scout GigE, Руководство пользователя

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AW00011916000 Standard Features
Basler scout GigE 299
12.9.5 Balance White Auto
Balance White Auto is the "automatic" counterpart to manually setting the white balance. The
balance white auto function is only available on color models.
Automatic white balancing is a two-step process. First, the Balance Ratio Abs parameter values for
red, green, and blue are each set to 1.5. Then, assuming a "gray world" model, the Balance Ratio
Abs parameter values are automatically adjusted such that the average values for the "red" and
"blue" pixels match the average value for the "green" pixels.
The balance white auto function uses Auto Function AOI 2 and can only be operated in the "once"
mode of operation.
If Auto Function AOI 2 does not overlap the Image AOI (see the "Auto Function AOI" section) the
pixel data from Auto Function AOI 2 will not be used to control the white balance of the image.
However, as soon as the Balance White Auto function is set to "once" operation mode, the Balance
Ratio Abs parameter values for red, green, and blue are each set to 1.5. These settings will control
the white balance of the image.
For information on the white balance feature, see Section 10.3.1 on page 181 .
To use the balance white auto function, carry out the following steps:
1. Select Auto Function AOI2.
2. Set the position and size of Auto Function AOI2.
3. Enable the balance white auto function by setting it to "once".
You can carry out steps 1 to 3 from within your application software by using the Basler pylon API.
The following code snippet illustrates using the API to use the auto function:

Selecting and setting Auto Function AOI2: See the "Auto Function AOI" section above.

Enabling the balance white auto function and selecting the "once" mode of operation:
// Select the AOI to use for auto white balancing
// Currently AOI2 is predefined to gather the pixel data needed for
// automatic white balancing
// Set position and size of the auto function AOI
Camera.AutoFunctionAOISelector.SetValue( AutoFunctionAOISelector_AOI2 );
Camera.AutoFunctionAOIOffsetX.SetValue( 0 );
Camera.AutoFunctionAOIOffsetY.SetValue( 0 );
Camera.AutoFunctionAOIWidth.SetValue( Camera.AutoFunctionAOIWidth.GetMax() );
Camera.AutoFunctionAOIHeight.SetValue( Camera.AutoFunctionAOIHeight.GetMax() );
// Set the mode of operation for balance white auto function
Camera.BalanceWhiteAuto.SetValue( BalanceWhiteAuto_Once );