Gamma Correction - Basler ace acA640-90gm User Manual

The balance ratio value can range from 0.00 to 15.98. But you should be aware that if you set the
balance ratio for a color to a value lower than 1, this will not only decrease the intensity of that color
relative to the other two colors, but will also decrease the maximum intensity that the color can
achieve. For this reason, we don't normally recommend setting a balance ratio less than 1 unless
you want to correct for the strong predominance of one color.
To set the Balance Ratio parameter for a color:
Set the Balance Ratio Selector to red, green, or blue.
Set the Balance Ratio Abs parameter to the desired value for the selected color.
You can set the Balance Ratio Selector and the Balance Ratio Abs parameter value from within your
application software by using the Basler pylon API. The following code snippet illustrates using the
API to set the selector and the parameter value:
Camera.BalanceRatioSelector.SetValue( BalanceRatioSelector_Green );
Camera.BalanceRatioAbs.SetValue( 1.20 );
You can also use the Basler pylon Viewer application to easily set the parameters.
For more information about the pylon Viewer, see Section 3.1.1 on
8.5.2

Gamma Correction

The gamma correction feature lets you modify the brightness of the pixel values output by the
camera's sensor to account for a non-linearity in the human perception of brightness. There are two
modes of gamma correction available on the camera: sRGB and User.
sRGB Gamma
When the camera is set for sRGB gamma correction, it automatically sets the gamma correction to
adjust the pixel values so that they are suitable for display on an sRGB monitor. If you will be
displaying the images on an sRGB monitor, using this type of gamma correction is appropriate.
User Gamma
With User type gamma correction, you can set the gamma correction value as desired.
To accomplish the correction, a gamma correction value (γ) is applied to the brightness value (Y) of
each pixel according to the following formula:
Y
⎛
uncorrected
-------------------------- -
Y =
⎝
corrected
Y
Basler ace GigE
γ
⎞
×
Y
⎠
max
max
Color Creation and Enhancement
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