F_VN_HoughCircles

Search for circles using the Hough transform.
Can use available TwinCAT Job Tasks for executing parallel code regions.
Can return partial results when canceled by Watchdog.

Syntax

Definition:

FUNCTION F_VN_HoughCircles : HRESULT
VAR_INPUT
    ipSrcImage    : ITcVnImage;
    ipCircles     : Reference To  ITcVnContainer;
    fInvAccuRatio : LREAL;
    fMinDist      : LREAL;
    hrPrev        : HRESULT;
END_VAR

Inputs

Name	Type	Description
ipSrcImage	ITcVnImage	Source image (USINT, 1 channel, gray-level)
ipCircles	Reference To ITcVnContainer	Returns a container which is filled with the found circles (ContainerType_Vector_TcVnVector3_REAL; Each container element contains the x coordinate of the circle center [0], the y coordinate of the circle center [1], and the radius [2], respectively. Non-zero interface pointers are reused.)
fInvAccuRatio	LREAL	Inverted ratio of the accumulator size in relation to the source image's size (must be > 0. A value of 2 means that the size is halved in both directions.)
fMinDist	LREAL	Smallest allowed distance of two circles (must be > 0)
hrPrev	HRESULT	HRESULT indicating the result of previous operations (If SUCCEEDED(hrPrev) equals false, no operation is executed.)

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