F_VN_ScharrFilterExp

Syntax

Definition:

FUNCTION F_VN_ScharrFilterExp : HRESULT
VAR_INPUT
    ipSrcImage       : ITcVnImage;
    ipDestImage      : Reference To  ITcVnImage;
    eDestDepth       : ETcVnElementType;
    eFilterDirection : ETcVnFilterDirection;
    fScale           : LREAL;
    fDelta           : LREAL;
    eBorderType      : ETcVnBorderInterpolationMethod;
    hrPrev           : HRESULT;
END_VAR

Inputs

Name	Type	Description
ipSrcImage	ITcVnImage	Source image
ipDestImage	Reference To ITcVnImage	Destination image (An appropriate destination image will be created if required.)
eDestDepth	ETcVnElementType	Destination image depth
eFilterDirection	ETcVnFilterDirection	Filter direction
fScale	LREAL	Scale factor for the computed derivative values
fDelta	LREAL	Delta value that is added to the results prior to storing them in dest
eBorderType	ETcVnBorderInterpolationMethod	Image border handling
hrPrev	HRESULT	HRESULT indicating the result of previous operations (If SUCCEEDED(hrPrev) equals false, no operation is executed.)

Return value

HRESULT

Further information

The function F_VN_ScharrFilterExp is the expert version of F_VN_ScharrFilter. It contains additional parameters.

Parameter

Original image

The original image ipSrcImage can have any format.

Result image

The result image ipDestImage returns the filter result and has the same format as the original image ipSrcImage.

Result depth

The result depth eDestDepth defines which element type the result image ipDestImage has. A larger element type can display more information.

Filter direction

The filter direction eFilterDirection defines whether the Scharr filter is applied to the image in the X-direction (TCVN_FD_X) or in the Y-direction (TCVN_FD_Y).

Scaling

The result of the Scharr operation is multiplied by the scaling factor fScale.

Delta

The constant delta fDelta is added to the result of the Scharr operation after scaling with fScale.

Border extrapolation

The method of border extrapolation eBorderType defines how non-existent pixels are extrapolated beyond the image border in order to calculate the filter values at the image borders. For further details, see ETcVnBorderInterpolationMethod.

Application

hr := F_VN_ScharrFilterExp(
    ipSrcImage      :=  ipImageIn,
    ipDestImage     :=  ipImageRes,
    eDestDepth      :=  TCVN_ET_USINT,
    eFilterDirection:=  TCVN_FD_X,
    fScale          :=  1,
    fDelta          :=  0,
    eBorderType     :=  TCVN_BIM_DEFAULT,
    hrPrev          :=  hr,
);

Samples

Edge detection filters

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