TcVnParamsBlobDetection

Offers parameters for blob detection

Syntax

Definition:

struct TcVnParamsBlobDetection
{
    bool                 bFilterByArea;
    bool                 bFilterByCircularity;
    bool                 bFilterByConvexity;
    bool                 bFilterByEccentricity;
    bool                 bFilterByInertiaRatio;
    float                fMinArea;
    float                fMaxArea;
    float                fMinCircularity;
    float                fMaxCircularity;
    float                fMinConvexity;
    float                fMaxConvexity;
    float                fMinEccentricity;
    float                fMaxEccentricity;
    float                fMinInertiaRatio;
    float                fMaxInertiaRatio;
    ETcVnThresholdType   eThresholdType;
    float                fMinThreshold;
    float                fMaxThreshold;
    float                fThresholdStep;
    float                fMinBlobDistance;
    ULONG                nMinRepeatability;
    ETcVnBlobCombination eBlobCombination;
};

Parameters

Name

Type

Default

Description

bFilterByArea

bool

true

Enable filtering by area (fMinArea <= area <= fMaxArea); strongly recommended to activate for filtering noise with fMinArea.

bFilterByCircularity

bool

false

Enable filtering by circularity (fMinCircularity <= circularity(4pi * area / perimeter^2) <= fMaxCircularity).

bFilterByConvexity

bool

false

Enable filtering by convexity (fMinConvexity <= convexity(area / hullArea) <= fMaxConvexity).

bFilterByEccentricity

bool

false

Enable filtering by eccentricity (fMinEccentricity <= eccentricity <= fMaxEccentricity).

bFilterByInertiaRatio

bool

false

Enable filtering by inertia ratio (fMinInertiaRatio <= inertia ratio <= fMaxInertiaRatio).

fMinArea

float

10

Min estimated blob area in pixel

fMaxArea

float

100000000

Max estimated blob area in pixel

fMinCircularity

float

0

Min circularity (1.0: ideal circle, < 1: less circular, 0: not circular at all)

fMaxCircularity

float

1

Max circularity (1.0: ideal circle, < 1: less circular, 0: not circular at all)

fMinConvexity

float

0

Min convexity (1.0: blob fully convex, < 1: less convex)

fMaxConvexity

float

1

Max convexity (1.0: blob fully convex, < 1: less convex)

fMinEccentricity

float

0

Min eccentricity (0.0: circular, 1.0: linear)

fMaxEccentricity

float

1

Max eccentricity (0.0: circular, 1.0: linear)

fMinInertiaRatio

float

0

Min inertia ratio (1.0: equal width and height, 0.0: linear)

fMaxInertiaRatio

float

1

Max inertia ratio (1.0: equal width and height, 0.0: linear)

eThresholdType

ETcVnThresholdType

TT_BINARY

Threshold type for internally applied threshold method (OTSU_XXX only supported for USINT images).

fMinThreshold

float

30

Threshold to start with (if fThresholdStep > 0, otherwise this is the only threshold used).

fMaxThreshold

float

225

Threshold to end with (if fThresholdStep > 0, otherwise this value is not used).

fThresholdStep

float

0

Sets to 0 if only 1 threshold should be used (much faster than multiple thresholds and combining the results).

fMinBlobDistance

float

5

Minimum distance between the center points of two different blobs (only used if fThresholdStep > 0; if distance < fMinBlobDistance, the blobs are treated as the same).

nMinRepeatability

ULONG

2

Minimum number of threshold steps, for which the same contour has to be detected (only used if fThresholdStep > 0; same means center point distance < fMinBlobDistance).

eBlobCombination

ETcVnBlobCombination

BC_MEDIAN_THRESHOLD

Selects, which of the multi-threshold blob contours should be returned.