F_VN_WhiteBalance
Calculates the white balance ratios for a RGB image. Uses the green channel as a reference and computes the relative ratios for the red and blue channels. Requires a non-reflecting, not overexposed white colored object (e.g. a sheet of paper) in at least 100 pixels of the image to provide reasonable results. The resulting ratios can then be set on the camera (multiply with existing ratios), or applied in the PLC via MultiplyImageWithVector.
Syntax
Definition:
FUNCTION F_VN_WhiteBalance : HRESULT
VAR_INPUT
ipSrcImage : ITcVnImage;
ipDestImage : Reference To ITcVnImage;
fRatioRed : Reference To REAL;
fRatioBlue : Reference To REAL;
nMaxValue : UDINT;
hrPrev : HRESULT;
END_VAR
Inputs
|
Name |
Type |
Description |
|---|---|---|
|
ipSrcImage |
Source image (3 channels (RGB), USINT or UINT) | |
|
ipDestImage |
Reference To ITcVnImage |
Destination image with white balance applied (optional, set to 0 if not required. An appropriate image will be created if required.) |
|
fRatioRed |
Reference To REAL |
Returns the ratio for the red channel |
|
fRatioBlue |
Reference To REAL |
Returns the ratio for the blue channel |
|
nMaxValue |
UDINT |
Specify the maximum pixel value that would be achieved by overexposure (usually 255 for 8 bit or 4095 for 12 bit data) |
|
hrPrev |
HRESULT indicating the result of previous operations (If SUCCEEDED(hrPrev) equals false, no operation is executed.) |
Return valueRequired License
TC3 Vision Base
System Requirements
Development environment | Target platform | PLC libraries to include |
|---|---|---|
TwinCAT V3.1.4024.54 or later | PC or CX (x64) with PL50, e.g. Intel 4-core Atom CPU | Tc3_Vision |