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Balance White Auto (dart E)#

The Balance White Auto camera feature automatically corrects color shifts in images acquired.

To correct color shifts manually, use the Balance White feature.

Using the Feature#

Enabling or Disabling Balance White Auto#

To enable or disable the Balance White Auto auto function, set the BalanceWhiteAuto parameter to one of the following operating modes:

  • Continuous: The camera adjusts the white balance continuously while images are being acquired.
  • Off: Disables the Balance White Auto auto function. The BalanceRatio parameters remain at the values resulting from the last automatic or manual adjustment.

How It Works#

Automatic white balancing is a two-step process:

  1. The camera compares the average gray values of the red, green, and blue pixels. It determines the color with the highest average gray value (i.e., the brightest color) and sets the BalanceRatio parameter value for this color to 1.
  2. The camera automatically adjusts the BalanceRatio parameter values of the other two colors until the average gray values for red, green, and blue are identical.

As a result, the BalanceRatio parameter is set to 1 for one color and to a value between 1 and ≈15.98 for the other two colors.

Example: Assume the green pixels in your image have the highest average gray value. If you enable the Balance White Auto auto function, the camera sets the BalanceRatio parameter value for green to 1. Then, the camera automatically adjusts the BalanceRatio parameter values for red and blue until the average gray values for red, green, and blue are identical. The new balance ratios could be, e.g., green = 1, red = 1.08789, and blue = 2.19678.

Info

  • To view the BalanceRatio parameter values for red, green, or blue, switch to the respective color channel using the BalanceRatioSelector.
  • When the camera is capturing images continuously, the auto function takes effect with a short delay. The first few images may not be affected by the auto function.

Sample Code#

// Enable Balance White Auto by setting the operating mode to Continuous
camera.BalanceWhiteAuto.SetValue(BalanceWhiteAuto_Continuous);

INodeMap& nodemap = camera.GetNodeMap();
// Enable Balance White Auto by setting the operating mode to Continuous
CEnumParameter(nodemap, "BalanceWhiteAuto").SetValue("Continuous");

// Enable Balance White Auto by setting the operating mode to Continuous
camera.Parameters[PLCamera.BalanceWhiteAuto].SetValue(PLCamera.BalanceWhiteAuto.Continuous);

/* Macro to check for errors */
#define CHECK(errc) if (GENAPI_E_OK != errc) printErrorAndExit(errc)
GENAPIC_RESULT errRes = GENAPI_E_OK;  /* Return value of pylon methods */
/* Enable Balance White Auto by setting the operating mode to Continuous */
errRes = PylonDeviceFeatureFromString(hdev, "BalanceWhiteAuto", "Continuous");
CHECK(errRes);

# Enable Balance White Auto by setting the operating mode to Continuous
camera.BalanceWhiteAuto.Value = "Continuous"

You can also use the pylon Viewer to easily set the parameters.