F_VN_ReferenceColorSimilarityExp_TcVnVector3_LREAL

Computes the similarity to a reference color for each pixel in the source image. (expert function)
Can use available TwinCAT Job Tasks for executing parallel code regions.
Can return partial results when canceled by Watchdog.

Syntax

Definition:

FUNCTION F_VN_ReferenceColorSimilarityExp_TcVnVector3_LREAL : HRESULT
VAR_INPUT
    ipSrcImage       : ITcVnImage;
    ipDestImage      : Reference To  ITcVnImage;
END_VAR
VAR_IN_OUT
    aRefColor        : TcVnVector3_LREAL;
END_VAR
VAR_INPUT
    fVariance        : REAL;
    fLuminanceWeight : REAL;
    hrPrev           : HRESULT;
END_VAR

Inputs

Name	Type	Description
ipSrcImage	ITcVnImage	RGB source image (USINT, 3 channels)
ipDestImage	Reference To ITcVnImage	Returns the similarity to aRefColor for each pixel in ipSrcImage (USINT, 1 channel. An appropriate destination image will be created if required.)
fVariance	REAL	Allowed color variance (0.1 - 0.3 might be a good start to try)
fLuminanceWeight	REAL	Weight the impact of the luminance ([0..1], e.g. set to 0 to be more resistant to unequal illumination, but might be required to differentiate between some colors)
hrPrev	HRESULT	HRESULT indicating the result of previous operations (If SUCCEEDED(hrPrev) equals false, no operation is executed.)

In/Outputs

Name	Type	Description
aRefColor	TcVnVector3_LREAL	Reference color (RGB, [0..255])

Return value

HRESULT

Further information

There are three ways to pass the reference color to the corresponding function:

As a trained color model of the type ITcVnColorModel
As a trained color model of the type ITcVnMlModel
Directly with values in a TcVnVector3_LREAL, see sample

To train a color model, a corresponding F_VN_TrainImageColor function must be used. The two color models differ only in the data type, functionally there are no differences. The ITcVnMlModel is the general data type for ML models for which there are also function blocks for loading and saving. Therefore, this data type and the corresponding functions should be used if the trained color model is to be saved to disk.

Samples

Color similarity with RGB reference color

Required 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