Struct cv::aruco::DetectorParameters#

struct DetectorParameters is used by ArucoDetector

Collaboration diagram for cv::aruco::DetectorParameters:

cv::aruco::DetectorParameters Node1 cv::aruco::DetectorParameters + markerBorderBits + minDistanceToBorder + minSideLengthCanonicalImg + perspectiveRemovePixelPerCell + polygonalApproxAccuracyRate + DetectorParameters() + readDetectorParameters() + writeDetectorParameters() Node2 int     Node2->Node1 +adaptiveThreshWinSizeMax +adaptiveThreshWinSizeMin +adaptiveThreshWinSizeStep +aprilTagDeglitch +aprilTagMaxNmaxima +aprilTagMinClusterPixels +aprilTagMinWhiteBlackDiff +cornerRefinementMaxIterations +cornerRefinementMethod +cornerRefinementWinSize ... Node3 double     Node3->Node1 +adaptiveThreshConstant +cornerRefinementMinAccuracy +errorCorrectionRate +maxErroneousBitsInBorderRate +maxMarkerPerimeterRate +minCornerDistanceRate +minMarkerDistanceRate +minMarkerPerimeterRate +minOtsuStdDev +perspectiveRemoveIgnoredMargin PerCell ... Node4 float     Node4->Node1 +aprilTagCriticalRad +aprilTagMaxLineFitMse +aprilTagQuadDecimate +aprilTagQuadSigma +minGroupDistance +minMarkerLengthRatioOriginal Img +relativeCornerRefinmentWin Size +validBitIdThreshold Node5 bool     Node5->Node1 +detectInvertedMarker +useAruco3Detection

cv::aruco::DetectorParameters Node1 cv::aruco::DetectorParameters + markerBorderBits + minDistanceToBorder + minSideLengthCanonicalImg + perspectiveRemovePixelPerCell + polygonalApproxAccuracyRate + DetectorParameters() + readDetectorParameters() + writeDetectorParameters() Node2 int     Node2->Node1 +adaptiveThreshWinSizeMax +adaptiveThreshWinSizeMin +adaptiveThreshWinSizeStep +aprilTagDeglitch +aprilTagMaxNmaxima +aprilTagMinClusterPixels +aprilTagMinWhiteBlackDiff +cornerRefinementMaxIterations +cornerRefinementMethod +cornerRefinementWinSize ... Node3 double     Node3->Node1 +adaptiveThreshConstant +cornerRefinementMinAccuracy +errorCorrectionRate +maxErroneousBitsInBorderRate +maxMarkerPerimeterRate +minCornerDistanceRate +minMarkerDistanceRate +minMarkerPerimeterRate +minOtsuStdDev +perspectiveRemoveIgnoredMargin PerCell ... Node4 float     Node4->Node1 +aprilTagCriticalRad +aprilTagMaxLineFitMse +aprilTagQuadDecimate +aprilTagQuadSigma +minGroupDistance +minMarkerLengthRatioOriginal Img +relativeCornerRefinmentWin Size +validBitIdThreshold Node5 bool     Node5->Node1 +detectInvertedMarker +useAruco3Detection

Detailed Description#

struct DetectorParameters is used by ArucoDetector

Constructor & Destructor Documentation#

DetectorParameters()#

cv::aruco::DetectorParameters::DetectorParameters()

Python:

cv.aruco.DetectorParameters() -> <aruco_DetectorParameters object>

Member Function Documentation#

readDetectorParameters()#

bool cv::aruco::DetectorParameters::readDetectorParameters(const FileNode & fn)

Python:

cv.aruco.DetectorParameters.readDetectorParameters(fn) -> retval

Read a new set of DetectorParameters from FileNode (use FileStorage.root()).

writeDetectorParameters()#

bool cv::aruco::DetectorParameters::writeDetectorParameters(
FileStorage & fs,
const String & name = String() )

Python:

cv.aruco.DetectorParameters.writeDetectorParameters(fs[, name]) -> retval

Write a set of DetectorParameters to FileStorage.

Member Data Documentation#

adaptiveThreshConstant#

double cv::aruco::DetectorParameters::adaptiveThreshConstant

constant for adaptive thresholding before finding contours (default 7)

adaptiveThreshWinSizeMax#

int cv::aruco::DetectorParameters::adaptiveThreshWinSizeMax

maximum window size for adaptive thresholding before finding contours (default 23).

adaptiveThreshWinSizeMin#

int cv::aruco::DetectorParameters::adaptiveThreshWinSizeMin

minimum window size for adaptive thresholding before finding contours (default 3).

adaptiveThreshWinSizeStep#

int cv::aruco::DetectorParameters::adaptiveThreshWinSizeStep

increments from adaptiveThreshWinSizeMin to adaptiveThreshWinSizeMax during the thresholding (default 10).

aprilTagCriticalRad#

float cv::aruco::DetectorParameters::aprilTagCriticalRad

reject quads where pairs of edges have angles that are close to straight or close to 180 degrees.

Zero means that no quads are rejected. (In radians) (default 10*PI/180)

aprilTagDeglitch#

int cv::aruco::DetectorParameters::aprilTagDeglitch

should the thresholded image be deglitched? Only useful for very noisy images (default 0).

aprilTagMaxLineFitMse#

float cv::aruco::DetectorParameters::aprilTagMaxLineFitMse

when fitting lines to the contours, what is the maximum mean squared error

aprilTagMaxNmaxima#

int cv::aruco::DetectorParameters::aprilTagMaxNmaxima

how many corner candidates to consider when segmenting a group of pixels into a quad (default 10).

aprilTagMinClusterPixels#

int cv::aruco::DetectorParameters::aprilTagMinClusterPixels

reject quads containing too few pixels (default 5).

aprilTagMinWhiteBlackDiff#

int cv::aruco::DetectorParameters::aprilTagMinWhiteBlackDiff

add an extra check that the white model must be (overall) brighter than the black model.

When we build our model of black & white pixels, we add an extra check that the white model must be (overall) brighter than the black model. How much brighter? (in pixel values, [0,255]), (default 5)

aprilTagQuadDecimate#

float cv::aruco::DetectorParameters::aprilTagQuadDecimate

April :: User-configurable parameters.

Detection of quads can be done on a lower-resolution image, improving speed at a cost of pose accuracy and a slight decrease in detection rate. Decoding the binary payload is still

aprilTagQuadSigma#

float cv::aruco::DetectorParameters::aprilTagQuadSigma

what Gaussian blur should be applied to the segmented image (used for quad detection?)

cornerRefinementMaxIterations#

int cv::aruco::DetectorParameters::cornerRefinementMaxIterations

maximum number of iterations for stop criteria of the corner refinement process (default 30).

cornerRefinementMethod#

int cv::aruco::DetectorParameters::cornerRefinementMethod

default value CORNER_REFINE_NONE

cornerRefinementMinAccuracy#

double cv::aruco::DetectorParameters::cornerRefinementMinAccuracy

minimum error for the stop cristeria of the corner refinement process (default: 0.1)

cornerRefinementWinSize#

int cv::aruco::DetectorParameters::cornerRefinementWinSize

maximum window size for the corner refinement process (in pixels) (default 5).

The window size may decrease if the ArUco marker is too small, check relativeCornerRefinmentWinSize. The final window size is calculated as: min(cornerRefinementWinSize, averageArucoModuleSize*relativeCornerRefinmentWinSize), where averageArucoModuleSize is average module size of ArUco marker in pixels. (ArUco marker is composed of black and white modules)

detectInvertedMarker#

bool cv::aruco::DetectorParameters::detectInvertedMarker

to check if there is a white marker.

In order to generate a “white” marker just invert a normal marker by using a tilde, ~markerImage. (default false)

errorCorrectionRate#

double cv::aruco::DetectorParameters::errorCorrectionRate

error correction rate respect to the maximum error correction capability for each dictionary (default 0.6).

markerBorderBits#

int cv::aruco::DetectorParameters::markerBorderBits

number of bits of the marker border, i.e. marker border width (default 1).

maxErroneousBitsInBorderRate#

double cv::aruco::DetectorParameters::maxErroneousBitsInBorderRate

maximum number of accepted erroneous bits in the border (i.e. number of allowed white bits in the border).

Represented as a rate respect to the total number of bits per marker (default 0.35).

maxMarkerPerimeterRate#

double cv::aruco::DetectorParameters::maxMarkerPerimeterRate

determine maximum perimeter for marker contour to be detected.

This is defined as a rate respect to the maximum dimension of the input image (default 4.0).

minCornerDistanceRate#

double cv::aruco::DetectorParameters::minCornerDistanceRate

minimum distance between corners for detected markers relative to its perimeter (default 0.05)

minDistanceToBorder#

int cv::aruco::DetectorParameters::minDistanceToBorder

minimum distance of any corner to the image border for detected markers (in pixels) (default 3)

minGroupDistance#

float cv::aruco::DetectorParameters::minGroupDistance = 0.21f

minimum average distance between the corners of the two markers in group to add them to the list of candidates

The average distance between the corners of the two markers is calculated relative to its module size (default 0.21).

minMarkerDistanceRate#

double cv::aruco::DetectorParameters::minMarkerDistanceRate

minimum average distance between the corners of the two markers to be grouped (default 0.125).

The rate is relative to the smaller perimeter of the two markers. Two markers are grouped if average distance between the corners of the two markers is less than min(MarkerPerimeter1, MarkerPerimeter2)*minMarkerDistanceRate.

default value is 0.125 because 0.125*MarkerPerimeter = (MarkerPerimeter / 4) * 0.5 = half the side of the marker.

Note

default value was changed from 0.05 after 4.8.1 release, because the filtering algorithm has been changed. Now a few candidates from the same group can be added to the list of candidates if they are far from each other.

See also

minGroupDistance.

minMarkerLengthRatioOriginalImg#

float cv::aruco::DetectorParameters::minMarkerLengthRatioOriginalImg

range [0,1], eq (2) from paper. The parameter tau_i has a direct influence on the processing speed.

minMarkerPerimeterRate#

double cv::aruco::DetectorParameters::minMarkerPerimeterRate

determine minimum perimeter for marker contour to be detected.

This is defined as a rate respect to the maximum dimension of the input image (default 0.03).

minOtsuStdDev#

double cv::aruco::DetectorParameters::minOtsuStdDev

minimum standard deviation in pixels values during the decodification step to apply Otsu thresholding (otherwise, all the bits are set to 0 or 1 depending on mean higher than 128 or not) (default 5.0)

minSideLengthCanonicalImg#

int cv::aruco::DetectorParameters::minSideLengthCanonicalImg

minimum side length of a marker in the canonical image. Latter is the binarized image in which contours are searched.

perspectiveRemoveIgnoredMarginPerCell#

double cv::aruco::DetectorParameters::perspectiveRemoveIgnoredMarginPerCell

width of the margin of pixels on each cell not considered for the determination of the cell bit.

Represents the rate respect to the total size of the cell, i.e. perspectiveRemovePixelPerCell (default 0.13)

perspectiveRemovePixelPerCell#

int cv::aruco::DetectorParameters::perspectiveRemovePixelPerCell

number of bits (per dimension) for each cell of the marker when removing the perspective (default 4).

polygonalApproxAccuracyRate#

double cv::aruco::DetectorParameters::polygonalApproxAccuracyRate

minimum accuracy during the polygonal approximation process to determine which contours are squares. (default 0.03)

relativeCornerRefinmentWinSize#

float cv::aruco::DetectorParameters::relativeCornerRefinmentWinSize

Dynamic window size for corner refinement relative to Aruco module size (default 0.3).

The final window size is calculated as: min(cornerRefinementWinSize, averageArucoModuleSize*relativeCornerRefinmentWinSize), where averageArucoModuleSize is average module size of ArUco marker in pixels. (ArUco marker is composed of black and white modules) In the case of markers located far from each other, it may be useful to increase the value of the parameter to 0.4-0.5. In the case of markers located close to each other, it may be useful to decrease the parameter value to 0.1-0.2.

useAruco3Detection#

bool cv::aruco::DetectorParameters::useAruco3Detection

enable the new and faster Aruco detection strategy.

Proposed in the paper: Romero-Ramirez et al: Speeded up detection of squared fiducial markers (2018) https://www.researchgate.net/publication/325787310_Speeded_Up_Detection_of_Squared_Fiducial_Markers

validBitIdThreshold#

float cv::aruco::DetectorParameters::validBitIdThreshold

range [0,1], define the acceptable threshold when comparing the detected marker to the dictionary during marker identification.

Source file#

The documentation for this struct was generated from the following file: