AdaptiveThreshold

Apply an adaptive threshold to a gray level image.
Can return partial results when canceled by Watchdog.

Syntax

Definition:

HRESULT AdaptiveThreshold(
    HRESULT                      hrPrev,
    ITcVnImage*                  ipSrcImage,
    ITcVnImage*&                 ipDestImage,
    double                       fMaxValue,
    ETcVnAdaptiveThresholdMethod eAdaptiveMethod = ATM_MEAN,
    ETcVnThresholdType           eThresholdType = TT_BINARY,
    ULONG                        nBlockSize = 3,
    double                       fConstant = 5
)

Parameters

Name	Type	Default	Description
hrPrev	HRESULT		HRESULT indicating the result of previous operations (If SUCCEEDED(hrPrev) equals false, no operation is executed.)
ipSrcImage	ITcVnImage*		Source image (1 channel, elements of type USINT)
ipDestImage	ITcVnImage*&		Destination image (An appropriate destination image will be created if required.)
fMaxValue	double		Value assigned to pixels for which the threshold condition is true
eAdaptiveMethod	ETcVnAdaptiveThresholdMethod	ATM_MEAN	Adaptive threshold method to be applied (MEAN: threshold value will be calculated as a mean of the nBlockSize x nBlockSize neighborhood of (x,y) minus fConstant. GAUSSIAN: threshold value is a weighted sum (cross-correlation with a Gaussian window) of the nBlockSize x nBlockSize neighborhood of (x,y) minus fConstant.
eThresholdType	ETcVnThresholdType	TT_BINARY	Threshold type to be applied (only BINARY and BINARY_INV are supported)
nBlockSize	ULONG	3	Size of the pixel neighborhood to calculate the local threshold (3, 5, 7, ...)
fConstant	double	5	Constant that is subtracted from the weighted mean of the pixel neighborhood, which leads to the local threshold

Return value

HRESULT

Required License

TC3 Vision Base

System Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT V3.1. 4024.44 or later	PC or CX (x64) with PL50, e.g. Intel 4-core Atom CPU	Tc3_Vision